Journal articles on the topic 'Ferrite'
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1
Wang, Wen Jie, Qing Jie Jiao, Chong Guang Zang, and Xiang Dong Zhu. "Study on the Absorption Properties of Spinel Type Ferrite Composite Coatings in the Low Frequency." Advanced Materials Research 415-417 (December 2011): 30–34. http://dx.doi.org/10.4028/www.scientific.net/amr.415-417.30.
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In the present study magneto-polymer composite coatings are fabricated using nano Zn ferrite, Mn ferrite, Ni ferrite, Zn-Mn ferrite and Zn-Ni ferrite by spraying method. The complex permeabilities, Complex permittivities and microwave absorbing properties within the low frequency of these composites were characterized and investigated. The results showed that the magnetism of the mixed spinel ferrites ( Mn ferrite, Zn-Ni ferrite, Zn-Mn ferrite) are strong but the dielectric properties are weaker, while the magnetism of the normal spinel ferrites (Zn ferrite) is the weakest but provide with a big storage capability of electric energy. The absorbing characteristics of the spinel ferrites are better at 300 kHz-1.5GHz, with minimum absorption of 12.5 dB and the maximum absorption at 480MHz, 1050 MHz and 1400 MHz. The microwave absorbing property of the mixed spinel ferrite Zn-Mn ferrite is best having the RL value being -42.5 dB at 1400GHz.
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Lee, Sang Bae, Se Ho Lee, D. H. Kim, Doug Youn Lee, Yong Keun Lee, Kyoung Nam Kim, and Kwang Mahn Kim. "In Vitro Cytotoxicity of Alginate-Encapsulating Ferrite Particles Using WST-1." Key Engineering Materials 284-286 (April 2005): 815–18. http://dx.doi.org/10.4028/www.scientific.net/kem.284-286.815.
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The purpose of this study was to evaluate the cytotoxicity of alginate-encapsulting ferrite particles in vitro. Various ferrite particles such as Ba-ferrite, Sr-ferrite, Co-ferrite, Co/Ni-ferrite were prepared by sol-gel process. Ferrite particles were encapsulated via calcium alginate process with different alginate contents ranged from 10 to 100 wt%. Mouse-fibroblastic NCTC L-929 cells were cultured in RPMI-1640 medium with 10% fetal bovine serum. The alginate-encapsulating ferrites were extracted in 5 ml of distilled water under pH 6.5 at 121°C for 1 h in accordance with ISO 10993-12. In vitro cytotoxicity was evaluated by WST-1. The results of this study indicated that the alginate-encapsulting ferrite particles affected cell viability by increasing alginate contents. Especially, alginate-encapsulating process were enhanced cell viability of ferrites such as Sr-ferrite, Co/Ni-ferrite, and Ba-Ferrite when alginate content was 10 wt%.
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Jimbo, Shotaro, and Shoichi Nambu. "Three-Dimensional Observation of Upper Bainite in the Initial Stage of Transformation in 0.4 wt%C TRIP Steel." Metals 13, no. 2 (February 10, 2023): 355. http://dx.doi.org/10.3390/met13020355.
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Three-dimensional microstructures of bainitic ferrites and prior austenite grains (PAGs) were observed in the initial stage of upper bainite transformation by using a serial sectioning technique and orientation analysis by electron back scattering diffraction (EBSD). The formation site of the bainitic ferrites was quantitatively evaluated by three-dimensional observation. It was revealed that the bainitic ferrites mainly form at the planes rather than the edges of prior austenite grain boundaries (PAGBs) and form on both sides of the PAGB plane. The effect of the orientation of the PAGs on the formation of the bainitic ferrites was also investigated. The bainitic ferrite has a small misorientation with the bainitic ferrite in the adjacent PAG across the PAGB. It is suggested that the reason for the formation of bainitic ferrite at the planes rather than edges of PAGBs is because it is difficult for bainitic ferrite to have a small misorientation with the bainitic ferrites in adjacent PAGs at edges.
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Soloman, M. A., Philip Kurian, and M. R. Anantharaman. "Dielectric and Mechanical Properties of Rubber Ferrite Composites Containing Barium Ferrite." Progress in Rubber, Plastics and Recycling Technology 18, no. 4 (November 2002): 269–82. http://dx.doi.org/10.1177/147776060201800404.
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The incorporation of various types of ferrites in rubber matrixes leads to the development of rubber ferrite composites (RFC). These RFC have a large number of applications as flexible magnets, high-tech sensors, for telecommunication and radiowave absorbers. Both natural and synthetic rubber has the potential of being value added by the incorporation of ferrites. Applications like microwave absorbers warrant that these composites have an appropriate dielectric strength with the required magnetic property. This can be achieved by synthesizing composites based on natural rubber and ferrites. In this paper we report the synthesis of RFC containing barium ferrite according to a specific recipe and its evaluation of dielectric and mechanical properties.
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Han, Fei, Haicheng Yu, Jeffrey Dessau, and Xianghai Chen. "Novel formation of Ferrite in Ingot of 0Cr17Ni4Cu4Nb Stainless Steel." ChemEngineering 2, no. 3 (September 10, 2018): 44. http://dx.doi.org/10.3390/chemengineering2030044.
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The ferrite body is the origin of crack and corrosion initiation of steels. Distribution and density of ferrite in seven steel ingots were examined by light optical microscopy and computational modeling, in the study, to explore the correlation of ferrite formation to chemical composition and the mushy zone temperature in ingot forming. The central segregation phenomenon in ferrite distribution was observed in all the examined steel specimens, except 0Cr17Ni4Cu4Nb stainless steel. No significant difference was found in the distribution and density of ferrite among zones of the surface, ½ radius, and core in neither the risers nor tails of 0Cr17Ni4Cu4Nb ingots. Additionally, fewer ferrites were found in 0Cr17Ni4Cu4Nb compared to other examined steels. The difference of ferrite formation in 0Cr17Ni4Cu4Nb elicited a debate on the traditional models explicating ferrite formation. Considering the compelling advantages in mechanical strength, plasticity, and corrosion resistance, further investigation on the unusual ferrite formation in 0Cr17Ni4Cu4Nb would help understand the mechanism to improve steel quality. In summary, we observed that ferrite formation in steel was correlated with the mushy zone temperature. The advantages of 0Crl7Ni4Cu4Nb in corrosion resistance and mechanical stability could be the result of fewer ferrites being formed and distributed in a scattered manner in the microstructure of the steel.
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Gao, Fen, Dong Lin Zhao, and Zeng Min Shen. "Preparation and Microwave Absorbing Properties of Cu-Doped Ni-Zn Spinel Ferrites." Advanced Materials Research 105-106 (April 2010): 293–96. http://dx.doi.org/10.4028/www.scientific.net/amr.105-106.293.
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Ni-Zn spinel ferrite and Cu-doped spinel ferrite were prepared by a conventional ceramic processing method. Microwave absorption, complex permittivity and permeability of the (Ni0.5Zn0.5)Fe2O4 and (Ni0.4Cu0.2Zn0.4)Fe2O4 spinel ferrites within the frequency range of 0.5-18 GHz were investigated. The reflection loss calculation results show that the Ni-Zn spinel ferrite and Cu-doped Ni-Zn spinel ferrite are good electromagnetic wave absorbers in the microwave range. The single layer (Ni0.4Cu0.2Zn0.4)Fe2O4 spinel ferrite absorber with a thickness of 9.2 mm achieved a reflection loss below -10 dB (90% absorption) at 0.5-2.3 GHz, and the minimum value is -35.63 dB at 1.1 GHz. When the first layer and second layer are (Ni0.5Zn0.5)Fe2O4 and (Ni0.4Cu0.2Zn0.4)Fe2O4 spinel ferrites respectively, the laminated absorbers with double spinel ferrite layers with a thickness of 3 mm achieved a reflection loss below -10 dB at 9.9-12.3 GHz, and the minimum value is -35.3 dB at 11.7 GHz.
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Torquato, Mattheus, Magno de Assis Verly Heringer, Eliel Gomes da Silva Neto, Emilson Ribeiro Viana Junior, and Ronaldo Sergio de Biasi. "Influence of cerium doping on the magnetic properties of a nanometric cobalt-zinc mixed ferrite." OBSERVATÓRIO DE LA ECONOMÍA LATINOAMERICANA 22, no. 7 (July 9, 2024): e5723. http://dx.doi.org/10.55905/oelv22n7-109.
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This study investigates the influence of cerium doping on the magnetic properties of nanometric-sized particles of a cobalt-zinc mixed ferrite with stoichiometric formula Co0.6Zn0.4Fe2O4. The effect of cerium doping was studied by producing a ferrite with the stoichiometric formula Co0.6Zn0.4Fe1.95Ce0.05O4 and comparing its magnetic properties with those of undoped cobalt-zinc ferrite and other ferrites. The samples were synthesized by sol-gel combustion and characterized by X-ray diffraction (XRD), vibrating-sample magnetometry (VSM) and ferromagnetic resonance (FMR). The XRD results confirm the synthesis of ferrite, the VSM results show that the saturation magnetization decreases with cerium doping and the FMR results show that the magnetocrystalline anisotropy decreases with cerium doping. Comparison with other ferrites suggests that doping with 5% cerium does not significantly decrease the microwave absorption of cobalt-zinc ferrite while protecting healthy cells in hyperthermy.
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de Campos, Marcos Flavio, and Daniel Rodrigues. "High Technology Applications of Barium and Strontium Ferrite Magnets." Materials Science Forum 881 (November 2016): 134–39. http://dx.doi.org/10.4028/www.scientific.net/msf.881.134.
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Ceramic magnets as barium ferrite or strontium ferrite have many applications in high technology. One of the reasons is the low cost when compared to competitor materials, as Alnico, MnBi, MnAl or NdFeB. In this study, the advantages and disadvantages of Ba and Sr ferrite magnets are discussed. One clear advantage is that ferrites are already oxides, and do not present the corrosion problems typical of NdFeB and other metallic alloys. As ferrites are oxides, the processing is much easier and cheaper. For example sintering can be done at air, and milling under wet condition. One of the main conclusions is the excellent ratio cost/benefit of ferrites, giving advantage in many applications. Special attention is given for application of ferrites in high efficiency motors.
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Thomas, Tina, Marius van Dijk, Marc Dreissigacker, Stefan Hoffmann, Hans Walter, Karl-Friedrich Becker, and Martin Schneider-Ramelow. "Ferrites in Transfer-Molded Power SiPs: Challenges in Packaging." Journal of Microelectronics and Electronic Packaging 17, no. 2 (April 1, 2020): 35–44. http://dx.doi.org/10.4071/imaps.1064487.
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Abstract Transfer-molding process is enjoying growing interest when aiming for novel high-power density system-in-packages (power SiPs), where not only transistors and diodes but also drivers, passives, coils, and transformers are supposed to be integrated in one package. Encapsulating modules in a transfer-molding process induces higher mechanical load onto module components compared with conventional silicone potting. Previous investigations have shown that integration of delicate components as ferrite cores into molded packages is not as trivial as integration of conventional surface-mount devices or power semiconductors; the brittle ferrites tend to fracture during the encapsulation process, resulting in higher ferrite core loss. The current study aims to identify main root causes for ferrite core cracking during manufacturing of molded power SiPs. The test vehicle is a symmetrical printed circuit board–based package with three pairs of E-shaped ferrite cores. The epoxy molding compound deployed here is characterized to enable filling simulations. Because technical datasheets of ferrites typically lack specifications of mechanical properties, ferrite materials are analyzed in more detail. Filling simulations and thermomechanical simulations are performed to gain insight into process-induced stress, which may induce cracks in the ferrites. In addition, different ferrite designs are evaluated regarding core losses and mechanical stability and, thus, their tendency to fracture.
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Habib, Shaimaa A., Samia A. Saafan, Talaat M. Meaz, Moustafa A. Darwish, Di Zhou, Mayeen U. Khandaker, Mohammad A. Islam, et al. "Structural, Magnetic, and AC Measurements of Nanoferrites/Graphene Composites." Nanomaterials 12, no. 6 (March 11, 2022): 931. http://dx.doi.org/10.3390/nano12060931.
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As a contribution to the graphene-based nanoferrite composites, this article is intended to present Mn, Co, and Co-Mn nanoferrites for the preparation and investigation of such samples. Nanoparticles of Co ferrite, Mn ferrite, and Co-Mn ferrite were chemically synthesized by the coprecipitation method. The composites of ferrite/graphene were made by incorporating weight ratios of 25% graphene to 75% ferrite. Various structural and characterizing investigations of ferrite samples and ferrite/graphene composites were performed, including XRD, EDX, SEM, VSM hysteresis loops, AC conductivity, and dielectric behavior. The investigations ensured the formation of the intended nanoferrite powders, each having a single-phase crystal structure with no undesired phases or elements. All samples exhibit a soft magnetic behavior. They show a semiconducting behavior of AC electrical conductivity as well. This was proved by the temperature dependence of the AC’s electrical conductivity. Whereas the dielectric function and loss tangent show an expected, well-explained behavior, the ferrite/graphene composite samples have lower saturation magnetization values, lower AC conductivity, and dielectric constant values than the pure ferrites but still have the same behavior trends as those of the pure ferrites. The values obtained may represent steps on developing new materials for expected applications, such as manufacturing supercapacitors and/or improved battery electrodes.
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Zhang, Chang Sen, and Leia Yang. "Microstructure and Magnetic Properties of La-Doped Barium-Ferrite." Advanced Materials Research 668 (March 2013): 706–9. http://dx.doi.org/10.4028/www.scientific.net/amr.668.706.
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The La-doped barium ferrites microparticles were successful synthesized by citrate sol-gel method. The structure, morphology and magnetic properties of the ferrite were characterized by X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), differential thermal analysis (TG-DSC) and superconducting quantum interference device (SQUID). The results showed that the average crystallite size of La-doped barium-ferrite decreased with increasing La content. The morphology of the barium ferrite was spherical particles; however, doped lanthanum, barium ferrite changed into laminated structure. In addition, doping lanthanum improved the magnetic properties of the ferrite. The saturation magnetization (Ms) of La-doped M-type barium ferrite 67.70emu/g, it was greater than the non-doped M-type barium ferrite 57.45emu/g.
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Bezerra, Daniella Cibele, Taciana Regina de Gouveia Silva, Edcleide Maria Araújo, Renê Anísio da Paz, and Ana Cristina Figueiredo de Melo Costa. "Development of Polyamide 6/Ferrite Composites for Absorbers of Electromagnetic Radiation." Materials Science Forum 660-661 (October 2010): 922–27. http://dx.doi.org/10.4028/www.scientific.net/msf.660-661.922.
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Composites consist of a mixture or combination of the two or more, micro or macro constituents that differ in shape and chemical composition and, in essence, are insoluble in one another. The polyamide is a polymer that presents dimensional stability, good resistance to impact without notch and excellent chemical resistance. Already the ferrites are absorbers of electromagnetic radiation and have versatility to be used as a composite of ferrites. The composite of polyamide6/ferrite was obtained by mixing 10 and 30wt.% of ferrite added to polyamide 6 in a Torque Rheometer Haake. The objective of this work was to develop of polyamide6/ferrite composites to be used as absorbers of electromagnetic radiation. The results were very promising and showed that occurs interaction between the ferrite and polyamide6.
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Thomas, Tina, Marius van Dijk, Marc Dreissigacker, Stefan Hoffmann, Hans Walter, Karl-Friedrich Becker, and Martin Schneider-Ramelow. "Ferrites in Transfer Molded Power SiPs – Challenges in Packaging." International Symposium on Microelectronics 2019, no. 1 (October 1, 2019): 000019–26. http://dx.doi.org/10.4071/2380-4505-2019.1.000019.
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Abstract Transfer-Molding-Process is enjoying growing interest when aiming for novel high-power density System-in-Packages (Power SiPs), where not only transistors and diodes, but also drivers, passives, coils and transformers are supposed to be integrated in one package. Encapsulating modules in a Transfer-Molding-Process induces higher mechanical load onto module components compared to conventional silicone potting. Previous investigations have shown, that integration of delicate components as ferrite cores into molded packages is not as trivial as integration of conventional Surface Mount Devices (SMDs) or power semiconductors; the brittle ferrites tend to fracture during the encapsulation process, resulting in higher ferrite core loss. The present study aims to identify main root causes for ferrite core cracking during manufacturing of molded Power SiPs. The test vehicle is a symmetrical Printed Circuit Board (PCB) based package with three pairs of E-shaped ferrite cores. The Epoxy Molding Compound (EMC) deployed here is characterized to enable filling simulations. Since technical datasheets of ferrites typically lack specifications of mechanical properties, ferrite materials are analyzed in more detail. Filling simulations and thermo-mechanical simulations are performed in order to gain insight into process-induced stress, which may induce cracks in the ferrites. In addition, different ferrite designs are evaluated regarding core losses and mechanical stability, and thus their tendency to fracture.
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Tambe, Sunanda, and R. Y. Borse. "Effects of Al Doping with Zinc Ferrite Nanoparticles on Structural, Magnetic and Dielectric Properties." Material Science Research India 19, no. 3 (December 30, 2022): 150–60. http://dx.doi.org/10.13005/msri/190306.
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Zinc ferrite nanoparticles have wide range of the applications in the field of Electronics, Optoelectronics, Magnetics, Solar cell, Photocatalysts. With Al doping we modify their structural, magnetic and electrical properties of zinc ferrite (ZnFe2O4). In the present studies, zinc ferrite nanoparticles were prepared by sol gel method using glycine as combustion agent. The effects of Al doping concentration on the structural, morphological, optical, magnetic and electrical properties of zinc ferrites were studied. In x-ray diffraction patterns analysis confirmed the formation of the cubic spinel structure. We characterise scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) in the current work to examine the morphology of the nanomaterials. The UV-Vis optical investigation showed that Al+3 doping increased absorbance and significantly decreased energy band gap value (1.90 eV-2.01 eV). The magnetic properties of zinc ferrite NPs were studied by using vibrating samples magnetometer which showed samples of pure zinc ferrites and Al-doped zinc ferrite with paramgnetism. Dielectric properties were studied from impedance analyser. When aluminium concentration increases in the zinc ferrites, dielectric characteristic results were obtained in which dielectric constant (ɛ'), dielectric loss (ɛ'') and tangent loss decreased. Also when frequency increases above all three dielectric parameters remains stable at high frequency. The obtained results of pure and Al doped Zn ferrite are useful for high frequency applications.
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Godha, Neha, Shubhang Vyas, Seema Kothari, and Suresh C. Ameta. "Use of Some Metal Ferrites as Catalyst in Aldol Condensation Reaction." Asian Journal of Organic & Medicinal Chemistry 7, no. 4 (2023): 304–8. http://dx.doi.org/10.14233/ajomc.2022.ajomc-p407.
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Two moles of benzaldehyde and one mole of acetone were condensed to afford dibenzalacetone in presence of sodium hydroxide. This aldol condensation was carried out in presence of magnetic copper ferrite, CuFe2O4, which was synthesized by hydrothermal method. Other magnetic ferrites (where M = Ni, Co, Zn and Mg) were also prepared. As-prepared metal ferrites were characterized by X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The copper ferrite was observed to be square shaped and particle size was 29.71 nm. The yield of product (dibenzalacetone) in presence of copper ferrite was found to be highest (90.6%). A comparative study was made with different metal ferrites as catalyst and found that the activity of metal ferrites followed the order: CuFe2O4 > ZnFe2O4 > NiFe2O4 > CoFe2O4 > MgFe2O4
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Pund, Sangita N., Pratik A. Nagwade, Arvind V. Nagawade, Shankar R. Thopate, and Arun V. Bagade. "Magnetic, morphological, and photocatalytic studies of Cu2+ doped Mg-Zn ferrite nanoparticles." IOP Conference Series: Materials Science and Engineering 1291, no. 1 (September 1, 2023): 012007. http://dx.doi.org/10.1088/1757-899x/1291/1/012007.
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Abstract Due to their distinctive characteristics, including their optical, catalytic, electrical, and magnetic properties, spinel ferrite nanoparticles attract more interest. Also, the substitution of transition metals like copper in ferrites has the potential to control their physical characteristics and could improve their catalytic and magnetic capabilities. Cu2+ doped Mg-Zn ferrite samples show a change in behaviour from superparamagnetic to soft ferrimagnetic. The photocatalytic studies for the CuxMg0.5Zn0.5-xFe2O4 (x= 0.1 to 0.5, and Δx= 0.1) nano-ferrites are conducted in visible light to investigate the methylene blue photodecomposition capability. The Cu-Mg-Zn nano-ferrites displayed unique behaviour in terms of Magnetic, and photocatalytic activity. These outcomes show that the Cu-Mg-Zn ferrite samples are apply to water remediation.
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Swaminathan, R., J. Woods, S. Calvin, Joseph Huth, and M. E. McHenry. "Microstructural Evolution Model of the Sintering Behaviour and Magnetic Properties of NiZn Ferrite Nanoparticles." Advances in Science and Technology 45 (October 2006): 2337–44. http://dx.doi.org/10.4028/www.scientific.net/ast.45.2337.
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The sintering of RF plasma synthesized NiZn ferrite nanoparticles was studied. The as-synthesized nanoparticles have been modeled as having a core-shell structure with richer Zn concentration on the surface. Most Zn cations occupy tetrahedral sites typical of zinc ferrites, while some of the Zn cations occupy tetrahedral sites in a (111) oriented surface layer in the form of ZnO. Ni and Fe cations show no evidence of such disorder and their positions are consistent with the bulk spinel structure. This core-shell structure evolves by decomposition of the as-synthesized nanoparticles into Ni-and Zn-rich ferrites followed by the decomposition of the Zn-rich ferrites into ZnO and -Fe2O3 during sintering of the nanoparticles. Within the core region, sintering causes Ni to exit the ferrite structure and be reduced to a metallic form, possibly via a NiO intermediate. The miscibility gap in the pseudo-binary ZnFe2O4/NiFe2O4 system was modeled using equilibrium solution data. Decomposition rates are interpreted considering inter-diffusion kinetics. Sintered nanoparticle compacts showed an evolution of a 4- phase mixture of ferrite + ZnO + -Fe2O3 + Ni with increasing sintering temperature. The average ferrite nanoparticle size is preserved up to very high sintering temperatures. These observations suggest that the ZnO shell contributes to the sintering process by surface diffusion while acting as a barrier to the growth of the ferrite core. Metal edge EXAFS patterns of the sintered compacts confirm that Fe transforms from a single ferrite phase into a mixture of -Fe2O3 and ferrite; ZnO content progressively increases with sintering temperature and elemental Ni evolves from the ferrite with increasing sintering temperature. The saturation magnetization and Curie temperature were observed to decrease as a function of sintering temperature, with an anomaly at the temperature where Ni starts to form. This is explained by Zn diffusing from the core depleting the ferrite and increasing the amount of non-magnetic ZnO in the shell. AC magnetic measurements also vary systematically with the microstructural evolution.
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Kostishin, V. G., R. I. Shakirzyanov, Igor M. Isaev, and Dmitry V. Salogub. "Study of radar absorbing characteristics of polymer composites with ferrite fillers." Industrial laboratory. Diagnostics of materials 88, no. 6 (June 26, 2022): 31–45. http://dx.doi.org/10.26896/1028-6861-2022-88-6-31-45.
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The search for effective radio-absorbing materials is an urgent task in solving the problems of electromagnetic compatibility, electromagnetic pollution, as well as stealth and stealth technologies. We present the results of studying the electrophysical and radio-absorbing characteristics of ferrite-polymer composites depending on the structure and magnetic properties of the ferrite filler, as well as the dielectric properties of the polymer matrix. The radio absorbing characteristics of composites F-42/Mn-Zn-ferrite, F-42/Ni-Zn-ferrite, F-42/yttrium iron garnet, F-42/BaFe12O19, F2M/LiMnZn-spinel, PS525/Mn-Zn -ferrite, PVA/Mn-Zn ferrite, and PVA/Ni-Zn ferrite have been studied. Experimental data on the reflection coefficient, determined on a metal plate in a frequency range of 0.1 – 7 GHz showed that spinel ferrites and composites containing them are effective radio absorbing materials. Analysis of the spectra of complex dielectric and magnetic permeability revealed that composites with spinel ferrites and yttrium iron garnet are characterized by a dispersion of the magnetic permeability, which arises as a result of resonance processes of the motion of domain boundaries and natural ferromagnetic resonance. Moreover, the electrical properties of ferrites can affect the high-frequency spectra of the permittivity and permeability. It is shown that the use of electroactive polymers as matrices makes it possible to increase dielectric losses in the high-frequency range and obtain the maximum attenuation of electromagnetic radiation within 25 – 40 dB with a width of 10 dB up to 2.5 GHz in 2 – 7 GHz range. The results obtained can be used in further study of the functional properties of radio-absorbing materials in the high-frequency range.
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Kruželák, Ján, Andrea Kvasničáková, Michaela Džuganová, Lenka Hašková, Rastislav Dosoudil, and Ivan Hudec. "Curing, Properties and EMI Absorption Shielding of Rubber Composites Based on Ferrites and Carbon Fibres." Polymers 15, no. 4 (February 9, 2023): 857. http://dx.doi.org/10.3390/polym15040857.
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In this work, magnetic soft ferrites, namely manganese–zinc ferrite, nickel–zinc ferrite and combinations of both fillers, were incorporated into acrylonitrile-butadiene rubber to fabricate composite materials. The total content of ferrites was kept constant—300 phr. The second series of composites was fabricated with a similar composition. Moreover, carbon fibres were incorporated into rubber compounds in constant amount—25 phr. The work was focused on investigation of the fillers on absorption shieling performance of the composites, which was investigated within the frequency range 1–6 GHz. Then, the physical–mechanical properties of the composites were evaluated. The achieved results demonstrated that the absorption shielding efficiency of both composite types increased with increasing proportion of nickel–zinc ferrite, which suggests that nickel–zinc ferrite demonstrated better absorption shielding potential. Higher electrical conductivity and higher permittivity of composites filled with carbon fibres and ferrites resulted in their lower absorption shielding performance. Simultaneously, they absorbed electromagnetic radiation at lower frequencies. On the other hand, carbon fibres reinforced the rubber matrix, and subsequent improvement in physical–mechanical properties was recorded.
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Othéro de Brito, Vera Lúcia, Francisco Cristóvão Lourenço de Melo, and Antônio Carlos da Cunha Migliano. "Microstructure and Complex Magnetic Permeability of Ni0.3Zn0.7Fe2O4 Ferrite." Materials Science Forum 591-593 (August 2008): 125–29. http://dx.doi.org/10.4028/www.scientific.net/msf.591-593.125.
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Ni-Zn ferrites are magnetic ceramics that are widely used in electric and electronic components. Among Ni1-xZnxFe2O4 ferrites, Ni0.3Zn0.7Fe2O4 is known to be the one of highest magnetic permeability in lower frequencies. This work is divided into two parts: the first part deals with the influence of sintering temperature and forming conditions on the microstructure of Ni0.3Zn0.7Fe2O4 ferrite. The second part deals with the influence of sintering temperature and environmental variations of temperature on the complex magnetic permeability of such ferrite. The ferrite studied in this work was fabricated by means of the conventional ceramic method. Complex magnetic permeability between 100 kHz – 100 MHz is discussed in relation to sintering temperature. The influence of environmental variations in temperature (-40 oC to +50 oC) on the complex magnetic permeability of the ferrite sintered at 1300 oC is discussed.
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Godha, Neha, and Suresh C. Ameta. "Use of Some Metalferrites as Catalyst in Benzil-Benzilicacid Rearrangement Reaction." Asian Journal of Chemical Sciences 13, no. 4 (July 18, 2023): 18–25. http://dx.doi.org/10.9734/ajocs/2023/v13i4246.
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Magnesium ferrite was used to catalyse the Benzil-Benzilic acid rearrangement reaction of 1,2-rearrangement of 1,2-diketones to α-hydroxy carboxylic acids in presence of a base. Magnesium ferrite was prepared by hydrothermal process. It was characterized by Field Emission Scanning Electron Microscopy (FESEM), X-Ray Diffraction Spectroscopy (XRD), and Energy Dispersive X-Ray Spectroscopy (EDX). The crystalline size of magnesium ferrite was found to have 82.47nm and these are irregular in shape. It was found that the yield of the product (benzilic acid) in the presence of Mg ferrite was 81.6%, which is almost 2.3 times the yield obtained in the absence of catalyst. A comparative study was made with different metal ferrites as catalyst and it was found that the activity of metal ferrites followed the order: MgFe2O4 > Cu Fe2O4 > Ni Fe2O4 > Co Fe2O4 > Zn Fe2O4
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Majid, Farzana, Amarah Nazir, Sadia Ata, Ismat Bibi, Hafiz Shahid Mehmood, Abdul Malik, Adnan Ali, and Munawar Iqbal. "Effect of Hydrothermal Reaction Time on Electrical, Structural and Magnetic Properties of Cobalt Ferrite." Zeitschrift für Physikalische Chemie 234, no. 2 (February 25, 2020): 323–53. http://dx.doi.org/10.1515/zpch-2019-1423.
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AbstractCobalt ferrite was synthesized by hydrothermal route in order to investigate the effect of hydrothermal reaction time on structural, magnetic and dielectric properties. The synthesized cobalt ferrite was characterized by X-ray diffraction, Fourier transform infrared and Vibrating-Sample Magnetometer (VMS). XRD data analysis confirmed the formation of cubic inverse spinel ferrite for complete time series as the high intensity peak corresponds to cubic normal spinel structure. The ionic radii, cation distribution among tetrahedral and octahedral sites, lattice parameters, X-ray density, bond lengths were also investigated cobalt ferrite prepared at different hydrothermal reaction time. The crystallite size was found to be in the range of 11.79–32.78 nm. Tolerance factor was near unity that also confirms the formation of cubic ferrites. VSM studies revealed the magnetic nature of cobalt ferrite. The coercivity (1076.3Oe) was observed for a sample treated for 11 h. The squareness ratio was 0.56 that is close to 0.5 which shows uniaxial anisotropy in cobalt ferrite. Frequency dependent dielectric properties i.e. dielectric constant, AC conductivity, tangent loss and AC resistivity are calculated with the help of Impedance Analyzer. Intrinsic cation vibration of cubic spinel ferrites are confirmed from FTIR analysis in the range of 400–4000 cm−1. In view of enhanced properties, this technique could possibly be used for the synthesis of cobalt ferrite for different applications.
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Abe, Masanori. "A Soft Solution Processing Technique for Preparing Ferrite Films and Their Applications." MRS Bulletin 25, no. 9 (September 2000): 51–55. http://dx.doi.org/10.1557/mrs2000.180.
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“Ferrite plating” is a typical “soft solution processing” (SSP) application; it enables the formation of oxide ferromagnetic films from an aqueous solution atT24−100°C under atmospheric pressure. Using ferrite plating, we can grow crystallized ferrite films of spinel-type (MFe)3O4(where M = Fe, Co, Ni, Zn, Al, Cr, etc.) in one step, requiring no heat treatment. This opens the door to fabricating novel ferritefilm devices using substrates of such nonheat-resistant materials as plastics and GaAs integrated circuits; conventional ferrite-film preparation techniques, such as sputtering, vacuum evaporation, molecularbeam epitaxy, liquid-phase epitaxy, and so on, require high temperatures (>∼600°C) for the crystallization of ferrites, which deteriorates the non-heat-resistant substrates. Ferrite plating is a unique technique that allows us to synthesize ferrite “films” by means of a wet chemical process. There are many techniques, for synthesizing ferrite “particles” from aqueous solutions, but no technique, to our knowledge, enables ferrite-film synthesis by a wet chemical process.
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Iacovita, Cristian, Gabriela Fabiola Stiufiuc, Roxana Dudric, Nicoleta Vedeanu, Romulus Tetean, Rares Ionut Stiufiuc, and Constantin Mihai Lucaciu. "Saturation of Specific Absorption Rate for Soft and Hard Spinel Ferrite Nanoparticles Synthesized by Polyol Process." Magnetochemistry 6, no. 2 (May 29, 2020): 23. http://dx.doi.org/10.3390/magnetochemistry6020023.
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Spinel ferrite nanoparticles represent a class of magnetic nanoparticles (MNPs) with enormous potential in magnetic hyperthermia. In this study, we investigated the magnetic and heating properties of spinel soft NiFe2O4, MnFe2O4, and hard CoFe2O4 MNPs of comparable sizes (12–14 nm) synthesized by the polyol method. Similar to the hard ferrite, which predominantly is ferromagnetic at room temperature, the soft ferrite MNPs display a non-negligible coercivity (9–11 kA/m) arising from the strong interparticle interactions. The heating capabilities of ferrite MNPs were evaluated in aqueous media at concentrations between 4 and 1 mg/mL under alternating magnetic fields (AMF) amplitude from 5 to 65 kA/m at a constant frequency of 355 kHz. The hyperthermia data revealed that the SAR values deviate from the quadratic dependence on the AMF amplitude in all three cases in disagreement with the Linear Response Theory. Instead, the SAR values display a sigmoidal dependence on the AMF amplitude, with a maximum heating performance measured for the cobalt ferrites (1780 W/gFe+Co), followed by the manganese ferrites (835 W/gFe+Mn), while the nickel ferrites (540 W/gFe+Ni) present the lowest values of SAR. The heating performances of the ferrites are in agreement with their values of coercivity and saturation magnetization.
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Vallet-Regí, M., S. Nicolopoulos, and J. M. González-Calbet. "HREM study of M, Y and W hexagonal type ferrites." Proceedings, annual meeting, Electron Microscopy Society of America 48, no. 4 (August 1990): 776–77. http://dx.doi.org/10.1017/s0424820100177015.
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Hexagonal ferrites have similar structural symmetries and are built by the same structural units. HREM has proved to be an excellent tool to identify individual stacking bloks, in M, Y and W hexaferrites.M, Y and W hexagonal type ferrites are well-known magnetic materials for applications. Some previous electron microscopy studies on these ferrites, reveal a variety of new phases coming from the microsyntactic intergrowth of M, Y and W structures. We report in this paper some microstructural features of these ferrites.BaFe12O19 (M) hexagonal ferrite was synthetized by using the standard ceramic technique. Crystals of Y type ferrite (nominal composition: BaLi0.5Fe0.5ZnFe16027) were prepared from stoichiometric amounts of BaCO3, ZnO and LiCO3. The synthesis of W-type ferrite (formula: Ba2Zn2Fe16027) is described elsewhere.Samples for observation were prepared by grinding powders of the above ferrites under acetone. HREM study was performed at the "Centro de Microscopía Electrónica, Univ. Complutense" using both 400 Kv and 200 Kv electron microscopes (JEM-400EX and JEM-200FX)
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Maklad, M. H., N. M. Shash, and H. K. Abdelsalam. "Synthesis, characterization and magnetic properties of nanocrystalline Ni1-xZnxFe2O4 spinels via coprecipitation precursor." International Journal of Modern Physics B 28, no. 25 (September 9, 2014): 1450165. http://dx.doi.org/10.1142/s0217979214501653.
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Nanocrystalline Ni 1-x Zn x Fe 2 O 4 (0.0 ≤ x ≤ 1.0) spinels are synthesized with a crystallite size range 5–2.2 nm, using different annealing temperatures. The influence of zinc content as well as grain size of ferrite on the ferrite microstructure, therefore on the physical properties of ferrite, are investigated by means of X-ray diffraction (XRD), scanning electron microscope (SEM), atomic force microscope (AFM), thermal analysis (TG, DTG, DSC) and infrared microscopy (IR). XRD results confirm single phase spinel structure for ferrite with Zn content x = 0.1 whereas second phase appears in higher zinc content ferrites. Thermal analysis shows an endothermic peak at ~ 720°C–750°C reveals the removal of defective surface layer existed on the surface of ferrite grains, which leads to cation redistribution. This is supported by the shift observed in IR bands as a result of the increase in zinc content or calcination temperature. Ferrite with composition Ni 0.7 Zn 0.3 Fe 2 O 4 calcined at 1000°C has the maximum saturation magnetization Ms among various compositions at different calcination temperatures. The Ms and the coercivity Hc of the ferrites nanoparticles are different from their corresponding bulk, which attributes to a defective surface layer, controlling the ultrafine particle behavior.
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Esmailian, Mohamad. "The Effect of Austenite Grain Size on the Growth of Different Ferrite Morphologies in a Nb-Microalloyed Steel." Defect and Diffusion Forum 289-292 (April 2009): 109–17. http://dx.doi.org/10.4028/www.scientific.net/ddf.289-292.109.
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The effect of austenite grain size on the austenite to ferrite transformation temperature and different ferrite morphologies and growth behaviour in one Nb-microalloyed (HSLA) steel has been investigated. Three different austenite grain sizes were selected and cooled for obtaining austenite to ferrite and growth behaviour of ferrite. Moreover, samples with specific austenite grain size have been quenched, partially, for investigation of the microstructural evolution. The optical microscopy observation suggested that the nucleation site of ferrite is on edge and inside of austenite grains in Nb- microalloyed steels. Micrographs of different ferrite morphologies show that at high temperatures, where diffusion rates are higher, grain boundary ferrite nucleates both at the edge and corner of austenite grains and grows into both austenite grains. As the temperature is lowered and the driving force for ferrite formation increases, intragranular sites inside the austenite grains become operative as nucleation sites and suppress the grain boundary ferrite growth. With more undercooling,intragranular ferrites are seen to nucleate and grow more extensively , indicating the beginning of displacive transformation. Furthermore, growth rate of intragranular ferrite shows that by increasing of austenite grain size, the growth rate of intragranular ferrite increases extensively and growth rate of grain boundary ferrite decreases. The growth kinetics of grain boundary ferrite shows that this transformation is controlled by the diffusion of carbon in the austenite ahead of the interface.
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Mastuki, Mastuki, Ichlas Wahid, and Djoko Sulistyono. "Karakterisasi Fase Kalsium Ferrite Berbasis Bahan Baku Pasir Besi Lumajang Dan Batu Kapur Tuban." MEKANIKA: Jurnal Teknik Mesin 8, no. 2 (January 31, 2023): 109–14. http://dx.doi.org/10.30996/jm.v8i2.8162.
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ABSTRAK
Penelitian sintesis kalsium ferrit pencampuran dari sintesis CaCO₃ yang berbahan dasar batu kapur tuban dan sintesis Fe₂O₃ yang berbahan dasar dari pasir besi lumajang. Dalam penelitian ini menggunakan variasi perbandingan massa dan temperatur tahan kalsinasi untuk mengetahui karakterisasi pembentukan kalsium ferrit. Pembentukan sintesis kalsium ferrit dari pencampuran sintesis CaCO₃ yang di proses dari batu kapur menggunakan metode karbonasi dan sintesis Fe₂O₃. Selanjutnya, di proses menggunakan metode kopresipitasi dengan variasi komposisi massa 1:6 dan 1:12 dengan penahanan waktu kalsinasi 3 jam pada temperatur suhu 800˚C, 900˚C dan 1000˚C. Untuk mengetahui karakterisasi sintesis kalsium ferrit menggunakan Difraktogram Sinar-X (XRD) dan Variasi komposisi suhu massa 1:6 dan 1:12 dengan penahanan kalsinasi 3 jam pada temperature 900ºC. untuk mengetahui butiran partikel kalsium ferit menggunakan pengujian Scanning Electron Microscope (SEM) .
Kata kunci: Kalsium ferrit , pasir besi , batu kapur, SEM
ABSTRACT
Research on the synthesis of mixed calcium ferrite from the synthesis of CaCO₃ which is made from Tuban limestone and the synthesis of Fe₂O₃ which is based on iron sand of Lumajang. In this study, variations in mass ratio and calcination resistance temperature were used to characterize the formation of calcium ferrite. The formation of calcium ferrite synthesis from mixing the synthesis of CaCO₃ which is processed from limestone using the method of carbonation and synthesis of Fe₂O₃. Furthermore, it was processed using the coprecipitation method with a mass composition variation of 1:6 and 1:12 with a holding time of 3 hours of calcination at temperatures of 800˚C, 900˚C and 1000˚C. To determine the characterization of the synthesis of calcium ferrite using X-Ray Diffractogram (XRD) and Variation of the mass temperature composition of 1:6 and 1:12 with 3 hours of calcination detention at a temperature of 900ºC. to determine the grains of calcium ferrite particles using Scanning Electron Microscope (SEM) testing.
Keywords: Calcium ferrite, iron sand, limestone, SEM
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Polevoy, S., G. Kharchenko, S. Tarapov, O. Kravchuk, K. Kurselis, B. Chichkov, and N. Slipchenko. "A magnetoactive metamaterial based on a structured ferrite." RADIOFIZIKA I ELEKTRONIKA 26, no. 1 (2021): 28–34. http://dx.doi.org/10.15407/rej2021.01.028.
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Subject and Purpose. The use of spatially structured ferromagnets is promising for designing materials with unique predetermined electromagnetic properties welcome to the development of magnetically controlled microwave and optical devices. The paper addresses the electromagnetic properties of structured ferrite samples of a different shape (spatial geometry) and is devoted to their research by the method of electron spin resonance (ESR). Methods and methodology. The research into magnetic properties of structured ferrite samples was performed by the ESR method. The measurements of transmission coefficient spectra were carried out inside a rectangular waveguide with an external magnetic field applied. Results. We have experimentally shown that over a range of external magnetic field strengths, the frequency of the ferromagnetic resonance (FMR) of grooved ferrite samples (groove type spatial geometry) increases with the groove depth. The FMR frequency depends also on the groove orientation relative to the long side of the sample. We have shown that as the external static magnetic field approaches the saturation field of the ferrite, the FMR frequency dependence on the external static magnetic field demonstrates "jump-like" behavior. And as the magnetic field exceeds the ferrite saturation field, the FMR frequency dependence on the groove depth gets a monotonic character and rises with the further growth of the field strength. Conclusion. We have shown that the use of structured ferrites as microwave electronics components becomes reasonable at magnetic field strengths exceeding the saturation field of the ferrite. At these fields, such a ferrite offers a monotonically increasing dependence of the resonant frequency on the external magnetic field and on the depth of grooves on the ferrite surface. Structured ferrites are promising in the microwave range as components of controlled filters, polarizers, anisotropic ferrite resonators since they can provide predetermined effective permeability and anisotropy
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Malathi, S., B. Sridhar, and Shiferaw Garoma Wayessa. "A Study of Lithium Ferrite and Vanadium-Doped Lithium Ferrite Nanoparticles Based on the Structural, Optical, and Magnetic Properties." Journal of Nanomaterials 2023 (February 14, 2023): 1–7. http://dx.doi.org/10.1155/2023/6752950.
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Lithium ferrite and vanadium-doped lithium ferrite have been extensively studied in recent research because of their potential applications in thermochromic materials, optoelectronic devices, and as a cathode material for rechargeable lithium batteries. In the present investigation, lithium ferrite and lithium vanadium ferrite are synthesized by sol–gel process. According to the Scherrer formula, the average particle size of lithium ferrite is 22 nm and that of vanadium-doped lithium ferrite is 29 nm. The lattice parameters and dislocation density are calculated from the X-ray diffraction results. According to the Fourier transform infrared spectroscopy analysis, ferrites were formed that exhibit strong absorption bands. According to the energy-dispersive X-ray analysis spectrum, the predicted elements are present in the sample. With the use of a vibrating sample magnetometer (VSM), the materials’ magnetic behavior is investigated.
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Tamaura, Y., T. Katsura, S. Rojarayanont, T. Yoshida, and H. Abe. "Ferrite Process; Heavy Metal Ions Treatment System." Water Science and Technology 23, no. 10-12 (May 1, 1991): 1893–900. http://dx.doi.org/10.2166/wst.1991.0645.
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The principle of the “Ferrite Process”, heavy metal ions treatment system, and the practically operated systems are presented. In the “Ferrite Process”, the heavy metal ions are incorporated into the lattice points of the ferrites in the course of the formation of the spinel structure by the oxidation of the Fe(II) ions. The ferrite formation reaction proceeds in two paths depending on the reaction pH; 1) the green rust path (pH 7-10), and 2) the γ-FeO(OH) path (pH 10.5-11). The mole ratio of the heavy metal ions incorporated into the lattice points to the Fetotal in the ferrites depends on the reaction pH and the mol ratio of the heavy metal ions in the reaction solution and to the Fe(II) ions added to the reaction solution. Ferrite Process is now practically adopted to the treatment of the laboratory waste waters at the universities and the institutes in Japan, to the treatment of the plating waste waters, and to the treatment of branching mine drainage waters. Since the ferrite sludge has a strong magnetic property, it is reused as a useful magnetic material.
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Koh, S. U., J. S. Kim, B. Y. Yang, and K. Y. Kim. "Effect of Line Pipe Steel Microstructure on Susceptibility to Sulfide Stress Cracking." Corrosion 60, no. 3 (March 1, 2004): 244–53. http://dx.doi.org/10.5006/1.3287728.
Full textAbstract:
Abstract The purpose of this experiment was to evaluate the effect of microstructure on sulfide stress cracking (SSC) properties of line pipe steel. Different kinds of microstructures, with chemical compositions identical to one steel heat, were produced by various thermomechanically controlled processes (TMCP). Coarse ferrite-pearlite, fine ferrite-pearlite, ferrite-acicular ferrite, and ferrite-bainite microstructures were investigated with respect to corrosion properties, hydrogen diffusion, and SSC behavior. SSC was evaluated using a constant elongation rate test (CERT) in a NACE TM0177 solution (5% sodium chloride [NaCl] + 0.5% acetic acid [CH3COOH], saturated with hydrogen sulfide [H2S]). The corrosion properties of steels were evaluated by potentiodynamic and linear polarization methods. Hydrogen diffusion through steel matrix was measured by an electrochemical method using a Devanathan-Stachurski cell. The effect of microstructure on cracking behavior also was investigated with respect to crack nucleation and propagation processes. Test results showed that ferrite-acicular ferrite microstructure had the highest resistance to SSC, whereas ferrite-bainitic and coarse ferritie-pearlitic microstructures had the lowest resistance. The high susceptibility to SSC inferritie-bainitic and coarse ferritic-pearlitic microstructures resulted from crack nucleation on hard phases such as grain boundary cementite in coarse ferritie-pearlitic microstructures and martensite/retained austenite (M/A) island in bainitic phases. Hard phase cementite at grain boundaries or M/A constituent in bainitic phases acted as crack nucleation sites and could be cracked easily under external stress; consequently, the susceptibility of steel to SSC increased. Metallurgical parameters including matrix structure and defects such as grain boundary carbides and inter-lath M/A constituents were more critical parameters for controlling SSC than the hydrogen diffusion rate.
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V, Nithya, and B. CHIRSABESAN. "Enhancing removal of pollutants from pharmaceutical wastewater using ferrites in Membrane Bioreactor: A promising technology for environmental sustainability." Asian Journal of Chemistry 35, no. 9 (August 31, 2023): 2225–31. http://dx.doi.org/10.14233/ajchem.2023.28101.
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Industrial wastewater contains various toxic and hazardous pollutants that require effective treatment to meet environmental regulations. In recent years, silver-doped ferrites have gained attention as promising materials for the treatment of industrial wastewater in membrane bioreactor (MBR). In this abstract, we will discuss the potential of silver-doped nickel ferrite (AgNiFe2O4) and silver-doped potassium ferrite (AgKFe2O4) was synthesized by sol-gel technique for the removal of pollutants from industrial wastewater. AgNiFe2O4 and AgKFe2O4 nanoparticles have been found to be effective for the removal of various pollutants, including heavy metals, organic compounds, and dyes, from industrial wastewater. Several studies have reported the successful application of silver-doped ferrites for the treatment of industrial wastewater. X-ray diffraction (XRD) pattern reveals the single phase cubic spinel structure with space group Fd-3m and Scanning electron microscope (SEM) confirmed the surface morphology of the synthesized nanoferrites. The use of AgNiFe2O4 and AgKFe2O4 has been found to significantly reduce the concentration of pollutants in wastewater, making it suitable for safe discharge into the environment. Furthermore, the regeneration of silver-doped ferrites has been found to be simple and cost-effective, making them an attractive alternative to conventional wastewater treatment methods. In conclusion, silver-doped nickel ferrite and silver-doped potassium ferrite have shown great potential for the treatment of pharmaceutical wastewater in MBR technique and ferrite materials make them promising candidates for future wastewater treatment technologies.
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Borecki, Michał, and Jan Sroka. "Methods of Assessing the Effectiveness of Filter Elements in Power Electronics." Energies 15, no. 14 (July 11, 2022): 5061. http://dx.doi.org/10.3390/en15145061.
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Newly constructed devices must meet a number of requirements in terms of the level of generated disturbances. To achieve an acceptable level in such devices, filters are installed—one of the cheapest ways to reduce interference in devices. One of the key elements of the filter that is responsible for the effectiveness of noise reduction are ferrites. Unfortunately, for various devices, an individual approach should be used in the selection of filters and, accordingly, ferrites. Due to the fact that ferrites from different manufacturers do not have standardized characteristics and information on their effectiveness, the selection of the right ferrite is a very time-consuming process. Therefore, this article will present the possibilities of quickly determining selected ferrite parameters in order to ensure the necessary level of noise reduction. For this purpose, assumptions from the CISPR 17 standard will be used. For selected types of ferrites, a large number of measurements were carried out in order to determine the optimal computational algorithm for adjusting ferrite characteristics to the designed conditions. The performance of these tests will be the basis for conducting tests on a larger number of ferrites, as well as for the development of possible standardization procedures.
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Zhou, Xiaobing, Youbing Li, and Qing Huang. "Preparation of Ti3C2Tx/NiZn Ferrite Hybrids with Improved Electromagnetic Properties." Materials 13, no. 4 (February 11, 2020): 820. http://dx.doi.org/10.3390/ma13040820.
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Ti3C2Tx/NiZn ferrite composites were synthesized using a co-precipitation hydrothermal method, and further consolidated using electric current field-assisted sintering technology. Nano NiZn ferrites were inserted into the Ti3C2Tx interlayers with uniform coverage on their surfaces. The incorporation of MXenes promoted the sintering kinetics of the NiZn ferrite ceramics. The electrical conductivity increased by six orders of magnitude compared to pure NiZn ferrite ceramics at room temperature. The present work provides a potential way to develop a large family of dense MXenes/ferrite multiphase ceramics. The multiphase ceramics could be potentially used for the on-beam-line higher-order mode load in advanced particle accelerators.
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Pussi, Katariina, Keying Ding, Bernardo Barbiellini, Koji Ohara, Hiroki Yamada, Chuka Onuh, James McBride, Arun Bansil, Ray K. Chiang, and Saeed Kamali. "Atomic Structure of Mn-Doped CoFe2O4 Nanoparticles for Metal–Air Battery Applications." Condensed Matter 8, no. 2 (May 24, 2023): 49. http://dx.doi.org/10.3390/condmat8020049.
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We discuss the atomic structure of cobalt ferrite nanoparticles doped with Mn via an analysis based on combining atomic pair distribution functions with high energy X-ray diffraction and high-resolution transmission electron microscopy measurements. Cobalt ferrite nanoparticles are promising materials for metal–air battery applications. Cobalt ferrites, however, generally show poor electronic conductivity at ambient temperatures, which limits their bifunctional catalytic performance in oxygen electrocatalysis. Our study reveals how the introduction of Mn ions promotes the conductivity of the cobalt ferrite electrode.
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Seyyed Ebrahimi, S. A., and Z. Pishgahi Fard. "An Investigation on the Optimum Conditions for Preparation of Pure Mn-Mg-Zn Ferrite Powder." Key Engineering Materials 336-338 (April 2007): 699–702. http://dx.doi.org/10.4028/www.scientific.net/kem.336-338.699.
Full textAbstract:
Manganese- Zinc ferrite is one of the most important spinel ferrites which is used in the electronics applications. These ferrites have an open lattice and can tolerate large amounts of the other metallic ions in their lattice. One of these divalent ions that can sit in the unit cell of Mn-Zn ferrites is Magnesium. Mn-Mg-Zn ferrites are new materials which is thought to be a good candidate for dielectric applications. In this work, a suitable relative values of raw materials for preparing pure Mn-Mg-Zn ferrite powder have been determined. It is carried out by using XRD experiments. The optimum temperature and time of calcination were also investigated by DTA/TGA, XRD and SEM techniques.
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Shedam, Rakesh M., Priyanka P. Kashid, Shridhar N. Mathad, Rahul B. Deshmukh, Mahadev R. Shedam, and Ashok B. Gadkari. "Ferrites gas sensors: A Review." Physics and Chemistry of Solid State 23, no. 3 (September 30, 2022): 626–40. http://dx.doi.org/10.15330/pcss.23.3.626-640.
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Gas sensors that are highly sensitive, stable, and selective are increasingly in demand to detect toxic gases. As a result of the need to monitor concentrations of these gases, humans, animals, and the environment are all protected. Metal ferrites (AFe2O3, where A is a metal) are a major factor in this field. The development of ferrite gas sensors has made remarkable advances in the detection of toxic gases from vehicle exhaust, biological hazards, environmental monitoring, and pollution monitoring over the last decade. It is important for ferrite gas sensors to consider parameters like phase formation, crystallite size, particle size, grain size, dopants, surface area, sensitivity, selectivity, operating temperature, gas concentration, response time, and recovery time. There are various materials for gas sensing use such as carbon monoxide (CO), carbon dioxide (CO2), methane (CH4), ethyl alcohol (C2H5OH), hydrogen sulfide (H2S), C2H5COOH, oxygen (O2), hydrogen (H2), chlorine (Cl2), NH3, C4H10, CH3COOH, gasoline, acetylene, petrol, and liquefied petroleum gas (LPG). Various methods are used to prepare ferrite gas sensors. Additionally, a brief description is provided of the various methods employed for synthesizing ferrite gas sensors. A comprehensive survey of ferrites as gas sensors, such as nickel, copper, zinc, cadmium, cobalt, magnesium, manganese, and multi-component ferrites, prepared by various methods.
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de la Torre, Ernesto, Ana Lozada, Maricarmen Adatty, and Sebastián Gámez. "Activated Carbon-Spinels Composites for Waste Water Treatment." Metals 8, no. 12 (December 16, 2018): 1070. http://dx.doi.org/10.3390/met8121070.
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Nowadays, mining effluents have several contaminants that produce great damage to the environment, cyanide chief among them. Ferrites synthesized from transition metals have oxidative properties that can be used for cyanide oxidation due to their low solubility. In this study, cobalt and copper ferrites were synthesized via the precipitation method, using cobalt nitrate, copper nitrate, and iron nitrate as precursors in a molar ratio of Co or Cu:Fe = 1:2 and NaOH as the precipitating agent. The synthesized ferrites were impregnated in specific areas on active carbon. These composites were characterized using X-Ray Diffraction (XRD) and Scanning Electron Spectroscopy (SEM). The XRD results revealed a cubic spinel structure of ferrites with a single phase of cobalt ferrite and two phases (copper ferrite and copper oxides) for copper. The CoFe2O4 impregnated on active carbon reached a cyanide oxidation of 98% after 8 h of agitation; the composite could be recycled five times with an 18% decrease in the catalytic activity. In cobalt ferrites, a greater dissolution of iron than cobalt was obtained. In the case of copper ferrite, however, the copper dissolution was higher. These results confirm that ferrites and activated carbon composites are a novel alternative for cyanide treatment in mining effluents.
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Glitzky, Carsten, Torsten Rabe, Markus Eberstein, Wolfgang A. Schiller, Jörg Töpfer, Stefan Barth, and Annette Kipka. "LTCC-Modules with Integrated Ferrite Layers—Strategies for Material Development and Co-Sintering." Journal of Microelectronics and Electronic Packaging 6, no. 1 (January 1, 2009): 49–53. http://dx.doi.org/10.4071/1551-4897-6.1.49.
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The integration of passive components (resistors, capacitors, inductors) into LTCC modules is a challenging task in multilayer ceramics technology. We report on multilayer assemblies consisting of combined layers of ferrite and dielectric LTCC tapes. Ni-Cu-Zn ferrites with maximum shrinkage at 900°C were processed to green tapes and laminated with dielectric LTCC tapes. Cosintering at 900°C led to multilayers with different defects such as incomplete densification of the ferrite layers, cracks, and warpage. Since ferrite tapes do not really allow compositional changes without deterioration of magnetic properties, the dielectric tape was modified with the following objectives: (i) matching of the shrinkage curves of dielectric and ferrite materials, (ii) adjusting the coefficients of thermal expansion to avoid cracking during cooling, and (iii) controlling of interface reactions. Using this concept we fabricated dense and defect-free multilayers consisting of dielectric and ferrite layers. However, compositional changes of the individual ferrite tapes require the development of a specific dielectric tape material with tailored properties.
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VYAS, SHUBANG, NEHA GODHA, RAKSHIT AMETA, and SURESH C. AMETA. "USE OF SOME METAL FERRITES IN THE REDUCTION OF 2,4,6- TRINITROPHENOL." Pollution Research 42, no. 01 (2023): 66–71. http://dx.doi.org/10.53550/pr.2023.v42i01.011.
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The noble-metal Nanocatalyst are widely used, but ferrite-based magnetic catalyst are rarely used. The magnetic copper ferrite, CuFe2 O4 catalyst was synthesized by hydrothermal method and used to reduce 2,4,6-trinitrophenol in presence of sodium borohydride. The copper ferrite was analysed by X-ray diffraction spectroscopy (XRD), Energy-dispersive X-ray spectroscopy (EDX), Scanning Electron Microscopy (SEM) and Fourier transform infrared (FTIR). The reduction of 2,4,6- trinitrophenol was observed in presence of copper ferrite as catalyst and sodium borohydride as the reductant. The conversion of 2, 4, 6-trinitrophenol to 2, 4, 6-triaminophenol was monitored by UV-Visible spectrophotometer. The effect of various parameters such as pH, concentration of nitro compound, and amount of catalyst were studied. The reaction was completed in 8 min in the presence of copper ferrite. It was interesting to note that copper ferrite exhibited higher rate of reduction in present of zinc and nickel ferrites, may due to synergetic effect otherwise they show very slow reduction.
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Gupta, Meenal, Anusree Das, Dipankar Das, Satyabrata Mohapatra, and Anindya Datta. "Chemical Synthesis of Rare Earth (La, Gd) Doped Cobalt Ferrite and a Comparative Analysis of Their Magnetic Properties." Journal of Nanoscience and Nanotechnology 20, no. 8 (August 1, 2020): 5239–45. http://dx.doi.org/10.1166/jnn.2020.18528.
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Lanthanum (La) and gadolinium (Gd) doped cobalt ferrite nanoparticles are synthesized using a soft chemical approach. The analysis of these ferrites using X-ray diffraction (XRD) and transmission electron microscopy (TEM) shows that lattice spacing decreases in the doped ferrite samples. Magnetization data indicates towards the decrease of saturation magnetisation but increase in coercivity with doping. Mössbauer spectroscopy measurements at room temperature indicate increased occupancy of trivalent cations at tetrahedral site. The addition of rare earth dopants reduces the hard-magnetic character of cobalt ferrite.
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Al-Senani, Ghadah M., Foziah F. Al-Fawzan, Rasmiah S. Almufarij, Omar H. Abd-Elkader, and Nasrallah M. Deraz. "Magnetic Behavior of Virgin and Lithiated NiFe2O4 Nanoparticles." Crystals 13, no. 1 (December 31, 2022): 69. http://dx.doi.org/10.3390/cryst13010069.
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A series of virgin and lithia-doped Ni ferrites was synthesized using egg-white-mediated combustion. Characterization of the investigated ferrites was performed using several techniques, specifically, X-ray Powder Diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and High-resolution transmission electron microscopy (HRTEM). XRD-based structural parameters were determined. A closer look at these characteristics reveals that lithia doping enhanced the nickel ferrite lattice constant (a), unit cell volume (V), stress (ε), microstrain (σ), and dislocation density (δ). It also enhanced the separation between magnetic ions (LA and LB), ionic radii (rA, rB), and bond lengths (A-O and B-O) between tetrahedral (A) and octahedral (B) locations. Furthermore, it enhanced the X-ray density (Dx) and crystallite size (d) of random spinel nickel ferrite displaying opposing patterns of behavior. FTIR-based functional groups of random spinel nickel ferrite were determined. HRTEM-based morphological properties of the synthesized ferrite were investigated. These characteristics of NiFe2O4 particles, such as their size, shape, and crystallinity, demonstrate that these manufactured particles are present at the nanoscale and that lithia doping caused shape modification of the particles. Additionally, the prepared ferrite’s surface area and total pore volume marginally increased after being treated with lithia, depending on the visibility of the grain boundaries. Last, but not least, as the dopant content was increased through a variety of methods, the magnetization of virgin nickel ferrite fell with a corresponding increase in coercivity. Uniaxial anisotropy, rather than cubic anisotropy, and antisite and cation excess defects developed in virgin and lithia-doped nickel ferrites because the squareness ratio (Mr/Ms) was less than 0.5. Small squareness values strongly recommend using the assessed ferrites in high-frequency applications.
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Jacobo, Silvia E., and P. G. Bercoff. "Coercivity Enhancement of Hexagonal Ferrites." Solid State Phenomena 202 (May 2013): 113–25. http://dx.doi.org/10.4028/www.scientific.net/ssp.202.113.
Full textAbstract:
Hexagonal ferrites have been widely used as permanent magnets since their discovery in the 1950s. In spite of their relatively modest magnetic properties, ferrite magnets still show the best performance-to-cost ratio and different investigators are trying to improve their magnetic capabilities by using different synthesis methods and compositions. Different scientific investigations and techniques (Mössbauer spectrometry, X-ray diffraction, and magnetic measurements) have allowed to optimize the permanent magnet properties of rare earth substituted hexagonal ferrite magnets such as La-Co and Nd-Co Sr and Ba ferrites. However, the solubility of rare earth ions in M-type hexaferrite is very low and their introduction leads to the formation of secondary phases, which must be avoided in order to obtain permanent magnets with optimal properties. We report results on enhanced coercivity of hexagonal Sr ferrites with Nd-Co substitution synthesized by the self-combustion method and calcination at 1100°C for two hours. The synthesis of this kind of ferrite is performed with a deficient, non-stoichiometric iron content (ratio Fe/ Sr1xRxof 10 and 11 instead of 12) in order to explore the presence of secondary phases. Comparison with samples of the same composition and stoichiometric formulation is made. Samples with lower iron content show the highest saturation magnetization, remanence and/or coercivity, indicating that the best results for applications of this ferrite will be obtained with an iron deficiency in the stoichiometric formulation. Nd substitution enhances the ferrite anisotropy and coercivity with respect to the unsubstituted sample.
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Shaikh, Melad, Mahendra Sahu, Kiran Kumar Atyam, and Kalluri V. S. Ranganath. "Surface modification of ferrite nanoparticles with dicarboxylic acids for the synthesis of 5-hydroxymethylfurfural: a novel and green protocol." RSC Advances 6, no. 80 (2016): 76795–801. http://dx.doi.org/10.1039/c6ra13354a.
Full textAbstract:
5-Hydroxymethylfurfural (5-HMF) has been synthesized under solvent free conditions using surface modified ferrite nanoparticles. The flexible ligand modified ferrites showed higher activity than rigid modified ferrites.
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Jonit, Siti Soleha, Madzlan Aziz, and Rita Sundari. "FESEM-EDX and CV Characteristics of Dopant (Mn, Co, Ni) Magnesium Ferrites." Advanced Materials Research 645 (January 2013): 150–53. http://dx.doi.org/10.4028/www.scientific.net/amr.645.150.
Full textAbstract:
Doping magnesium ferrites (MgFe2 O4) with Mn, Co and Ni, which were synthesized by sol gel method using citric acid and polyvinyl alcohol (P VA) and calcined at 500oC, showed interesting electrochemical featur es based on their cyclic voltammetric (CV) characteristics using 5 µL ferrite – poly vinylidene fluoride in ethano l deposited on a screen printed carbon electrode (SPCE) in a mixture of 1.0 M KOH and ferricyanide solution recorded with a scan rate of 0.02 Vs -1. The Mn doped magnesium ferrite (x = 0.9) showed the most remarkable CV performance over other doped element (Co and Ni) and un-doped magnesiu m ferrites. The surface morphology of doped ferrites was studied by applying a field emissi on scanning electron microscope (FESEM) in conjunction with an energy dispersive X-ray spect roscopy (EDX) analysis. The results revealed that Mn posed the highest percentage on the surface ( ≈ 21.5 %), followed by Co (≈ 19.5%) and Ni ( ≈ 6.7%) with respect to x = 0.9 of M0.9Mg0.1Fe 2 O4 (M = Co, Mn and Ni) at 500oC calcination. The study showed the possibility of yielding semi conducting ferrites using own fabricated magnesium ferrite and its metal doping.
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Kostishin, Vladimir G., Igor M. Isaev, and Dmitrij V. Salogub. "Radio-Absorbing Magnetic Polymer Composites Based on Spinel Ferrites: A Review." Polymers 16, no. 7 (April 6, 2024): 1003. http://dx.doi.org/10.3390/polym16071003.
Full textAbstract:
Ferrite-containing polymer composites are of great interest for the development of radar-absorbing and -shielding materials (RAMs and RSMs). The main objective of RAM and RSM development is to achieve a combination of efficient electromagnetic wave (EMW) absorption methods with advantageous technological and mechanical properties as well as acceptable weight and dimensions in the final product. This work deals with composite RAMs and RSMs containing spinel-structured ferrites. These materials are chosen since they can act as efficient RAMs in the form of ceramic plates and as fillers for radar-absorbing polymer composites (RAC) for electromagnetic radiation (EMR). Combining ferrites with conducting fillers can broaden the working frequency range of composite RAMs due to the activation of various absorption mechanisms. Ferrite-containing composites are the most efficient materials that can be used as the working media of RAMs and RSMs due to a combination of excellent dielectric and magnetic properties of ferrites. This work contains a brief review of the main theoretical standpoints on EMR interaction with materials, a comparison between the radar absorption properties of ferrites and ferrite–polymer composites and analysis of some phenomenological aspects of the radar absorption mechanisms in those composites.
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Walters, I., R. Shende, and J. A. Puszynski. "Hydrogen Production from Thermochemical Water-Splitting Using Ferrites Prepared by Solution Combustion Synthesis." Advances in Science and Technology 91 (October 2014): 32–38. http://dx.doi.org/10.4028/www.scientific.net/ast.91.32.
Full textAbstract:
Currently, there are several methods to produce spinel ferrite powder material such as sol-gel synthesis, self-propagating high-temperature synthesis (SHS), aerosol spray pyrolysis, and solution combustion synthesis (SCS). These methods have been shown to produce nominally phase pure ferrites for use in hydrogen generation by thermochemical water-splitting. Among these methods, the ferrites derived by SCS have not been fully investigated for hydrogen generation from thermochemical water-splitting. SCS, in general, has several advantages such as it being a simple synthesis that can be done relatively quickly and produces materials with high specific surface area. In this study, nickel, zinc, cobalt, and manganese ferrites were synthesized using SCS and analyzed by XRD, BET, and SEM. Each ferrite material was placed inside an Inconel tubular reactor and five consecutive thermochemical cycles to determine hydrogen production. The regeneration and water-splitting temperatures were performed with water-splitting and regeneration temperatures of 900°C and 1100°C, respectively. Nickel ferrite produced significantly higher average hydrogen volume as compared to the other ferrites over the five thermochemical cycles. However, all four ferrites showed a decrease in hydrogen volume generation with increase in consecutive water-splitting cycle, which could be due to the grain growth as observed by BET and SEM analyses.
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Chandrasekar, S., M. C. Shaw, and B. Bhushan. "Morphology of Ground and Lapped Surfaces of Ferrite and Metal." Journal of Engineering for Industry 109, no. 2 (May 1, 1987): 83–86. http://dx.doi.org/10.1115/1.3187112.
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Scanning electron microscope pictures of ground and lapped ferrite (sinfered magnetic ceramic) and steel surfaces and chips are studied and compared. These reveal considerably more plastic action associated with the formation of metal chips in fine grinding than for ferrite chips. Individual chips are an order of magnitude larger for metals than for ferrites. These results are consistent with the much greater specific grinding energy for metals than for ferrites. The depth of the plastically deformed layer beneath a ground surface revealed by etching corresponds closely with the depth of residual surface stress.
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Abd-Elkader, Omar H., Nasrallah M. Deraz, and Lotfi Aleya. "Corchorus Olitorius-Mediated Green Synthesis and Characterization of Nickel and Manganese Ferrite Nanoparticles." Symmetry 15, no. 5 (April 23, 2023): 965. http://dx.doi.org/10.3390/sym15050965.
Full textAbstract:
Developing a method for preparing Ni and Mn ferrites was the main objective of this study due to the importance of these materials in high-frequency applications. These ferrites were made by assisting combustion with dried leaves of Corchorus olitorius and then heating them to 700 °C. Several methods, including FTIR, XRD, TEM, and SEM/EDX, were used to characterize these ferrites. The thermal behavior, surface and magnetic properties of the as-prepared materials were determined. The results revealed that the method used is cheap, economical, environmentally friendly and makes it easy to produce the studied ferrites. FTIR, XRD, TEM, and SEM/EDX analyses show the formation of nanocrystalline ferrites with brittle, spongy and spinel-type structures, having two main vibration bands located around 400 cm−1 and 600 cm−1. However, TG-DTG results display the thermal behavior of different materials which consisted of unreacted oxides, carbon and the corresponding ferrites in the range of 300 °C to 600 °C. Moreover, complete conversion of the unreacted oxides to the equivalent ferrite was achieved by increasing heat treatment from 600 °C to 1000 °C. Ferrites are heated at 700 °C, which reduces their surface area. The magnetic properties of different ferrites calcined at 700 °C were estimated using the VSM technique. The magnetism of Fe-based materials containing Ni and Mn is 12.189 emu/g and 25.988 emu/g, respectively. Moreover, the squareness and coercivity of Ni ferrite are greater than for Mn ferrite.