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Journal articles on the topic 'Bulk oxides'

Author: Grafiati

Published: 6 September 2023

Last updated: 7 September 2023

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1

Köck, Eva-Maria, Michaela Kogler, Thomas Götsch, Bernhard Klötzer, and Simon Penner. "Structural and chemical degradation mechanisms of pure YSZ and its components ZrO2 and Y2O3 in carbon-rich fuel gases." Physical Chemistry Chemical Physics 18, no. 21 (2016): 14333–49. http://dx.doi.org/10.1039/c6cp02458k.

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2

D. A. Muller, T. Sorsch, S. Moccio, F. H. Baumann, K. Evans-Lutterodt, and G. Timp. "How Small Is Too Small ? Understanding The Electronic Structure Of Atomic-Scale Transistors." Microscopy and Microanalysis 5, S2 (August 1999): 120–21. http://dx.doi.org/10.1017/s1431927600013921.

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The transistors planned for commercial use ten years from now in many electronic devices will have gate lengths shorter than 130 atoms, gate oxides thinner than 1.2 nm of SiO2 and clock speeds in excess of 10 GHz. It is now technologically possible to produce such transistors with gate oxides only 5 silicon atoms thick[l]. Since at least two of those 5 atoms are not in a local environment similar to either bulk Si or bulk SiO2, the properties of the interface are responsible for a significant fraction of the “bulk” properties of the gate oxide. However the physical (and especially their electrical) properties of the interfacial atoms are very different from .bulk Si or bulk SiO2. Further, roughness on an atomic scale can alter the leakage current by orders of magnitude.In our studies of such devices, we found that thermal oxidation tends to produce Si/SiO2 interfaces with 0.1-0.2 nm rms roughness.

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3

Ali, A. A., F. A. Al-Sagheer, and M. I. Zaki. "Surface Texture of Microcrystalline Tunnel-Structured Manganese(IV) Oxides: Nitrogen Sorptiometry and Electron Microscopy Studies." Adsorption Science & Technology 20, no. 7 (September 2002): 619–32. http://dx.doi.org/10.1260/02636170260504314.

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Three different modifications of manganese(IV) oxide, viz. cryptomelane, nsutite and todorokite-like, were synthesized by hydrothermal methods. The bulk chemical composition, phase composition, crystalline structure and particle morphology of the resulting materials were determined by thermogravimetry, atomic absorption spectroscopy, X-ray diffractometry, infrared spectroscopy and scanning electron microscopy. The surface chemical composition, texture and structure were assessed using X-ray photoelectron microscopy, nitrogen sorptiometry and high-resolution electron microscopy. The results highlighted the hydrothermal conditions under which such tunnel-structured modifications of manganese(IV) oxide can be successfully synthesized. Moreover, they revealed that (i) the bulk was microcrystalline, (ii) the crystallites were either fibrils (cryptomelane and nsutite) or rod-like (todorokite) with low-index exposed facets, (iii) the surface chemical composition mostly reflected that of the bulk and (iv) the surface texture was linked with high specific areas, slit-shaped mesopores associated with particle interstices and micropores which allowed surface accessibility to the bulk tunnels of the test oxides. The application of such test oxides as shape-selective oxidation catalysts appears worthy of investigation.

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4

García-Muñoz, J. L., J. Fontcuberta, M. Suaaidi, and X. Obradors. "Bandwidth narrowing in bulk magnetoresistive oxides." Journal of Physics: Condensed Matter 8, no. 50 (December 9, 1996): L787—L793. http://dx.doi.org/10.1088/0953-8984/8/50/003.

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5

Wachs, Israel E., and Kamalakanta Routray. "Catalysis Science of Bulk Mixed Oxides." ACS Catalysis 2, no. 6 (May 22, 2012): 1235–46. http://dx.doi.org/10.1021/cs2005482.

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6

Şeker, Şükran. "Determination and Evaluation of Metal Oxide Toxicity on Dermal Fibroblasts by Using the Impedance-Based Assay System." Proceedings 2, no. 25 (December 5, 2018): 1557. http://dx.doi.org/10.3390/proceedings2251557.

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Metal oxides have been widely used in various applications such as biomedical, commercial and environmental, due to their unique physicochemical properties. As the use of metal oxides increase worldwide, their exposure to the living systems also increases. It is therefore necessary to understand their potential harmful effects on human and environment health. In this study, dermal fibroblasts were exposed to bulk zinc oxide (0.1, 1, 10, 50, and 100 μg/mL) for 6 and 48 h. After exposure, changes in cell viability, morphology, membrane damage and zinc oxide uptake were investigated. The response of dermal fibroblasts exposed to different concentrations of bulk zinc oxide was monitored in real-time using an impedance-based assay system. Results demonstrated that zinc oxide at 50 and 100 μg/mL showed significant toxic effects compared to the control cell cultures.

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7

Barad, Chen, Giora Kimmel, Hagay Hayun, Dror Shamir, Kachal Hirshberg, and Yaniv Gelbstein. "Phase Stability of Nanocrystalline Grains of Rare-Earth Oxides (Sm2O3 and Eu2O3) Confined in Magnesia (MgO) Matrix." Materials 13, no. 9 (May 11, 2020): 2201. http://dx.doi.org/10.3390/ma13092201.

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Rare-earth (RE) oxides are important in myriad fields, including metallurgy, catalysis, and ceramics. However, the phase diagram of RE oxides in the nanoscale might differ from the phase diagrams for bulk, thus attracting attention nowadays. We suggest that grain size in the nanoscale also determines the obtained crystallographic phase along with temperature and pressure. For this purpose, nanoparticles of Sm2O3 and Eu2O3 were mixed in an inert MgO matrix via the sol-gel method. This preparation method allowed better isolation of the oxide particles, thus hindering the grain growth process associated with increasing the temperature. The mixed oxides were compared to pure oxides, which were heat-treated using two methods: gradual heating versus direct heating to the phase transition temperature. The cubic phase in pure oxides was preserved to a higher extent in the gradual heating treatment compared to the direct heating treatment. Additionally, in MgO, even a higher extent of the cubic phase was preserved at higher temperatures compared to the pure oxide, which transformed into the monoclinic phase at the same temperature in accordance with the phase diagram for bulk. This indicates that the cubic phase is the equilibrium phase for nanosized particles and is determined also by size.

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8

Wang, Xiao, and Alfred Ludwig. "Recent Developments in Small-Scale Shape Memory Oxides." Shape Memory and Superelasticity 6, no. 3 (August 26, 2020): 287–300. http://dx.doi.org/10.1007/s40830-020-00299-7.

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Abstract This review presents an overview of the developments in small-scale shape memory materials: from alloys to oxides and ceramics. Shape memory oxides such as zirconia, different ferroelectric perovskites and VO2-based materials have favorable characteristics of high strength, high operating temperature and chemical resistance, which make this class of shape memory materials interesting for special applications, e.g., in harsh environments or at the nanoscale. Because of the constraint and mismatch stress from neighboring grains in polycrystalline/bulk oxides, the transformation strain of shape memory oxides is relatively small, and micro-cracks can appear after some cycles. However, recent progress in shape memory oxide research related to small-scale approaches such as decreasing the amounts of grain boundaries, strain-engineering, and application in the form of nanoscale thin films shows that some oxides are capable to exhibit excellent shape memory effects and superelasticity at nano/micro-scales. The materials systems ZrO2, BiFO3, and VO2 are discussed with respect to their shape memory performance in bulk and small-scale.

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9

Grilli, Maria Luisa. "Metal Oxides." Metals 10, no. 6 (June 19, 2020): 820. http://dx.doi.org/10.3390/met10060820.

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Oxide materials in bulk and thin film form, and metal oxide nanostructures exhibit a great variety of functional properties which make them ideal for applications in solar cells, gas sensors, optoelectronic devices, passive optics, catalysis, corrosion protection, environmental protection, etc. [...]

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10

Tam, C. Y., and C. H. Shek. "Oxidation Behavior of Cu60Zr30Ti10 Bulk Metallic Glass." Journal of Materials Research 20, no. 6 (June 1, 2005): 1396–403. http://dx.doi.org/10.1557/jmr.2005.0182.

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The oxidation kinetics of Cu60Zr30Ti10 bulk metallic glass and its crystalline counterpart were studied in oxygen environment over the temperature range of 573–773 K. The oxidation kinetics, measured with thermogravimetric analysis, of the metallic glass follows a linear rate law between 573 and 653 K and a parabolic rate law between 673 and 733 K. It was also found that the oxidation activation energy of metallic glass is lower than that of its crystalline counterpart. The x-ray diffraction pattern showed that the oxide layer is composed of Cu2O, CuO, ZrO2, and metallic Cu. Cu enrichment on the topmost oxide layer of the metallic glass oxidized at 573 K was revealed by x-ray photoelectron spectroscopy while there was a decrease in Cu content in the innermost oxide layer. The oxide surface morphologies observed from scanning electron microscopy showed that ZrO2 granules formed at low temperatures while whiskerlike copper oxides formed at higher temperatures.

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11

Nnamdi, Amaeze Henry, Tam-Miette Dawarri Briggs, Oluwaseun Olusola Togunde, and Henry Ebele Obanya. "Antagonistic Effects of Sublethal Concentrations of Certain Mixtures of Metal Oxide Nanoparticles and the Bulk (Al2O3, CuO, and SiO2) on Gill Histology in Clarias gariepinus." Journal of Nanotechnology 2019 (June 12, 2019): 1–11. http://dx.doi.org/10.1155/2019/7686597.

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Background. The effect of nanoparticles (NPs) on aquatic environments is poorly studied. Aim. This study evaluates the toxicity of joint effects of these different metal nanoparticles and their bulk in mixtures (Al2O3, CuO, and SiO2) on fish using histological biomarker. Materials and Methods. The bulk and nano sizes of three salts (Al2O3, CuO, and SiO2) were used. Nanosizes ranged from 25 nm to 100 nm. The juvenile fishes of Clarias gariepinus (mean Length: 12.3 ± 3.5 cm; mean weight: 18.52 ± 6.41 g) were used for the acute and chronic toxicity tests. They were exposed to 7 mg/L each of the bulk and nano sizes of the three metallic oxides either singly or in mixtures for 28 days. The basis for the sublethal concentration was that the 96 hr acute toxicity of the varied sizes of the three metallic oxides was nontoxic up to the concentrations of 100 mg/L with no significant mortality at the highest exposure concentrations. The gills were collected for histopathology. Results. Of the three metal oxide nanoparticles, SiO was the most toxic, with histopathological alteration index (HAI) of 20.0, followed by nano-CuO (HAI, 10.0) and nano-Al2O3 (HAI, 2.0). In single exposure, the gill alterations include high frequencies of erosion of gill lamella (EGL), hypertrophy (HPT), oedema (OD), and necrosis (N). Less damage was observed at the combination of the metal oxide nanoparticles of SiO + Al2O3, SiO + CuO and SiO + Al2O3 + CuO in equal (1 : 1—HAI, 2 and 6; 1 : 1 : 1—HAI, 6) and unequal ratios (1 : 2—HAI, 16 and 6; 2 : 1—HAI, 8 and 6). Similarly, all bulk combinations were also antagonistic except for the equal ratio of bulk CuO (HAI, 20) and bulk Al2O3 (HAI, 10) that gave additive effect with HAI of 32. Conclusion. The joint actions of nano Al2O3 and CuO with SiO produced a low toxic effect, unlike the high toxicity of their single trials; this also indicates that nano Al2O3 and CuO are antagonists. Similarly, among the bulk metal oxides (SiO, Al2O3, and CuO), CuO was the most toxic. Bulk SiO and Al2O3 are antagonistic on the effects of CuO on the fish gill. There is need to properly document the ecological implications of nanoparticles in the aquatic environment.

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12

Yamada, Y., and Y. Shiohara. "Bulk Processing of High-Temperature Superconducting Oxides." IEEE Translation Journal on Magnetics in Japan 9, no. 3 (May 1994): 95–103. http://dx.doi.org/10.1109/tjmj.1994.4565865.

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13

Morales, J. R., J. E. Garay, M. Biasini, and W. P. Beyermann. "Magnetic characterization of bulk nanostructured iron oxides." Applied Physics Letters 93, no. 2 (July 14, 2008): 022511. http://dx.doi.org/10.1063/1.2959070.

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14

Guo, Rui-Fen, Hai-Rong Mao, Zhi-Tao Zhao, and Ping Shen. "Ultrafast high-temperature sintering of bulk oxides." Scripta Materialia 193 (March 2021): 103–7. http://dx.doi.org/10.1016/j.scriptamat.2020.10.045.

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15

Belmont, O., P. Tixador, J. G. Noudem, P. Ferracci, L. Porcar, D. Bourgault, J. M. Barbut, and R. Tournier. "Fault current limiter using bulk oxides superconductors." European Physical Journal Applied Physics 2, no. 2 (May 1998): 139–43. http://dx.doi.org/10.1051/epjap:1998176.

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16

Laruelle, S., M. Figlarz, and B. Bouchet-Fabre. "Octahedra's packing in bulk amorphous tungsten oxides." Journal of Non-Crystalline Solids 192-193 (December 1995): 116–20. http://dx.doi.org/10.1016/0022-3093(95)00434-3.

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17

Chaudhry, M. Iqbal, and W. B. Berry. "Passivation of β–SiC surface with native and nonnative oxides." Journal of Materials Research 4, no. 6 (December 1989): 1491–94. http://dx.doi.org/10.1557/jmr.1989.1491.

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The passivation characteristics of various insulators are evaluated for the β–SiC surface. It is found that wet thermal oxides yield minimum electrical defects at the oxide-SiC interface. Dry thermal oxide results in too much charge either at the oxide-SiC interface or in the bulk. It is also shown that anodic aluminum oxide seems to possess suitable electrical properties for the fabrication of MOS structures on SiC, whereas the CVD silicon nitride proved to be the worst.

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18

Fiebig, Manfred. "Phase engineering in oxides by interfaces." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 370, no. 1977 (October 28, 2012): 4972–88. http://dx.doi.org/10.1098/rsta.2012.0204.

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Optical second harmonic generation and piezoresponse force microscopy are used to investigate manifestations of ordered states directly related to the presence of an oxide interface. Three examples, each with a very different scope, are reviewed in order to highlight the richness of interface-related phenomena in oxides. (i) The orbital states involved in the emergence of an interfacial conducting state in LaAlO 3 /SrTiO 3 heterostructures are investigated, which reveal a surprising decoupling of orbital and transport properties; (ii) the distribution of ferroelectric and antiferromagnetic domains in epitaxial films of the multiferroic hexagonal manganites is investigated, which reveals striking differences to the corresponding bulk crystals; and (iii) the distribution of trimerization–polarization domains in the hexagonal manganites is investigated, which reveals the presence of topologically protected domain walls with properties different from the bulk.

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19

Ramiro, J., L. Galán, E. García Camarero, I. Montero, and Y. Laaziz. "X-ray photoelectron spectroscopy of electrodeposited cadmium mercury telluride thin films and their native surface oxides." Journal of Materials Research 16, no. 7 (July 2001): 1942–52. http://dx.doi.org/10.1557/jmr.2001.0266.

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Electrodeposited thin films of CdTe and CdxHg1−xTe with 1 − x = 0 and approximately 0.1 were characterized by x-ray photoelectron spectroscopy. The composition of the bulk and the thickness and composition of the native surface oxide before and after Ar+ ion sputtering were determined. A surface oxide layer 20-Å thick constituted mainly of alloyed TeO2 and CdO was found over a nearly stochiometric bulk. Chemical diffusion of Hg, Cd, and Te to the surface was observed. Hg appears to inhibit oxidation of the telluride, mainly of Te. Ar sputtering removed undesirable oxides and impurities off the films.

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20

Barannyk, Andrii. "Bulk chemical composition of the mountainous meadowy brown soils of the Ukrainian Carpathians and processes of its transformation." Visnyk of the Lviv University. Series Geography, no. 51 (December 27, 2017): 11–20. http://dx.doi.org/10.30970/vgg.2017.51.8733.

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The features of the bulk chemical composition of mountainous meadowy brown soils and anthropogenically-modified soils of the Svydovets and Chornogora arrays of the Ukrainian Carpathians are investigated. The ratio of the oxides content of the most important chemical elements of the mineral part of mountainous meadowy brown soils and parent material is determined. The basic transformation processes of the mineral part of the studied soils and parent material are established. The peculiarity of the bulk chemical composition of meadow brown soils is the high content of silicon oxides, and the high content of aluminum oxides and iron oxides. Their total content is within 94 %. This indirectly indicates a significant chemical homogeneity of the soil with the parent material. The relative accumulation of SiO2 in the upper genetic horizons of the soil profile is due to the physical disintegration of silicate rocks. Its relative bulk content is gradually reduced from 76.10–77.43 % to 72.28–76.93 % in the transition to a parent material. It was established, that the removal of sesquioxides beyond the boundary of the soil profile leads to the formation of a depleted soil profile on aluminum oxides and iron oxides, as we compare with unchanged parent material. Absolute values of the indicators of leakage factor of alkaline earth metals grow in the direction towards to the parent material. This indicates about intensive development of erosion processes in the upper part of the soil profile. This is due to the physical and chemical disintegration of aluminosilicates and the removal of compounds of disintegration into the lower soil genetic horizons. The analysis of the results of balance of bulk reserves of oxides testified, that during the formation of the mountainous meadowy brown soils of the Ukrainian Carpathians, oxides of trivalent metals (aluminum and iron) and compounds of alkaline earth metals are subjected to removal from the genetic horizons of the soil profile. Quantitative bulk chemical analysis didn’t show any significant differences in the material composition between the mountainous meadowy brown soils and the mountainous meadowy brown anthropogenically altered soil. Key words: mountainous meadow brown soils, bulk chemical composition, Svydovets and Chornogora arrays, Ukrainians Carpathians.

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21

Zhao, Kaixuan, Zhijie Yang, Huiying Wei, Jinxin Guo, Yanzhao Yang, and Jingjing Wei. "Controlled syntheses of monodispersed metal oxide nanocrystals from bulk metal oxide materials." CrystEngComm 22, no. 28 (2020): 4790–96. http://dx.doi.org/10.1039/d0ce00193g.

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22

Patel, A. K., A. R. Umatt, and B. S. Chakrabarty. "Nano Crystallite ZrO₂, La₂O₃and CeO₂: Synthesis, Characterization and their Properties." Solid State Phenomena 209 (November 2013): 212–15. http://dx.doi.org/10.4028/www.scientific.net/ssp.209.212.

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It is well known that a minor addition of rare earth oxides can provide a beneficial effect towards various catalytic reactions. Use of rare earth oxide in different applications could improve commercial productivity in an affordable way. Among the rare earth oxides, ZrO2, La2O3 and CeO2 are very interesting due to their various characteristics showing a large range of applications in organic reactions. The changes in the molecular properties of materials at the nano scale level greatly enhance their physical properties as well as chemical properties and activity. Due to the extremely small size of the particles, an increased surface area is provided to the reactant enabling more molecules to react at the same time, thereby speeding up the process. In this work, the enhancement in the catalytic activity of these nano structured rare earth oxides has been studied under different reaction conditions. Nano crystalline ZrO2, La2O3 and CeO2 samples were synthesized using precipitation method and optimum reaction conditions have been established; whereas the corresponding bulk samples were synthesized by combustion method. The identification of phase and crystalline size of synthesized oxides have been done by X-ray diffraction, the band gape of these three oxides in both the forms has been analyzed by UV absorbance and surface area has been determined by gas adsorption analysis (BET). Moreover their different properties and the activity of nano crystallite oxides have also been compared with their bulk counterparts. Even the activity of ZrO2 is also compared with the rare earth oxides La2O3 and CeO2.

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23

Meisenheimer, P. B., and J. T. Heron. "Oxides and the high entropy regime: A new mix for engineering physical properties." MRS Advances 5, no. 64 (2020): 3419–36. http://dx.doi.org/10.1557/adv.2020.295.

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AbstractHistorically, the enthalpy is the criterion for oxide materials discovery and design. In this regime, highly controlled thin film epitaxy can be leveraged to manifest bulk and interfacial phases that are non-existent in bulk equilibrium phase diagrams. With the recent discovery of entropy-stabilized oxides, entropy and disorder engineering has been realized as an orthogonal approach. This has led to the nucleation and rapid growth of research on high-entropy oxides – multicomponent oxides where the configurational entropy is large but its contribution to its stabilization need not be significant or is currently unknown. From current research, it is clear that entropy enhances the chemical solubility of species and can realize new stereochemical configurations which has led to the rapid discovery of new phases and compositions. The research has expanded beyond studies to understand the role of entropy in stabilization and realization of new crystal structures to now include physical properties and the roles of local and global disorder. Here, key observations made regarding the dielectric and magnetic properties are reviewed. These materials have recently been observed to display concerted symmetry breaking, metal-insulator transitions, and magnetism, paving the way for engineering of these and potentially other functional phenomena. Excitingly, the disorder in these oxides allows for new interplay between spin, orbital, charge, and lattice degrees of freedom to design the physical behavior. We also provide a perspective on the state of the field and prospects for entropic oxide materials in applications considering their unique characteristics.

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24

Lim, Zhi Shiuh, Hariom Jani, T. Venkatesan, and A. Ariando. "Skyrmionics in correlated oxides." MRS Bulletin 46, no. 11 (November 2021): 1053–62. http://dx.doi.org/10.1557/s43577-021-00227-9.

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AbstractWhile chiral magnets, metal-based magnetic multilayers, or Heusler compounds have been considered as the material workhorses in the field of skyrmionics, oxides are now emerging as promising alternatives, as they host special correlations between the spin–orbital–charge–lattice degrees of freedom and/or coupled ferroic order parameters. These interactions open new possibilities for practically exploiting skyrmionics. In this article, we review the recent advances in the observation and control of topological spin textures in various oxide systems. We start with the discovery of skyrmions and related quasiparticles in bulk and heterostructure ferromagnetic oxides. Next, we emphasize the shortcomings of implementing ferromagnetic textures, which have led to the recent explorations of ferrimagnetic and antiferromagnetic oxide counterparts, with higher Curie temperatures, stray-field immunity, low Gilbert damping, ultrafast magnetic dynamics, and/or absence of skyrmion deflection. Then, we highlight the development of novel pathways to control the stability, motion, and detection of topological textures using electric fields and currents. Finally, we present the outstanding challenges that need to be overcome to achieve all-electrical, nonvolatile, low-power oxide skyrmionic devices. Graphical abstract

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25

Praig, Vera Gertraud, and Michael Stöger-Pollach. "Metallography of Low Alloy Cr-Mn Hot-Rolled Steel and Quantitative Evaluation of Grain Boundary- and Internal Oxides by TEM." Materials Science Forum 782 (April 2014): 284–87. http://dx.doi.org/10.4028/www.scientific.net/msf.782.284.

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Alloy elements undergo complex diffusion and segregation processes during steel production. Oxygen diffuses into the steel matrix and forms oxides at the surface (called scale), at the grain boundaries and within the grains. In our work we present assemblies and composition of various oxides found at the grain boundaries and within the grains of a low alloy Mn-Cr hot-rolled steel sheet. We utilise metallographic means (surface etching) and transmission electron microscopy (TEM). After etching we observe four zones of different composition: (i) the scale, followed by a decarburised metallic layer with (ii) oxidised grain boundaries, (iii) non-oxidised grain boundaries and last, (iv) the bulk. Via TEM, we analyse alloy element oxides at grain boundaries and within the grains with high spatial resolution. At the grain boundaries and within the grains we find oxides, such as Mn- or Cr oxides, rather than binary oxides (e.g. Fe-Mn- and Fe-Cr oxides) or even more complex oxides, such as Fe-Mn-Cr oxides. The oxide species found lie next to- or embedded amongst one another.

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26

Yang, Minghui, Michelle J. MacLeod, Franck Tessier, and Francis J. DiSalvo. "Mesoporous Metal Nitride Materials Prepared from Bulk Oxides." Journal of the American Ceramic Society 95, no. 10 (July 30, 2012): 3084–89. http://dx.doi.org/10.1111/j.1551-2916.2012.05351.x.

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27

Chuvil’deev, V. N., and E. S. Smirnova. "Phenomenological theory of bulk diffusion in metal oxides." Physics of the Solid State 58, no. 7 (July 2016): 1487–99. http://dx.doi.org/10.1134/s1063783416070118.

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28

Buciuman, Florina, Florin Patcas, Radu Craciun, and Dietrich R. T. Zahn. "Vibrational spectroscopy of bulk and supported manganese oxides." Physical Chemistry Chemical Physics 1, no. 1 (1999): 185–90. http://dx.doi.org/10.1039/a807821a.

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29

Carbonio, R. E., C. Fierro, D. Tryk, D. Scherson, and E. Yeager. "Perovskite-type oxides: Oxygen electrocatalysis and bulk structure." Journal of Power Sources 22, no. 3-4 (March 1988): 387–98. http://dx.doi.org/10.1016/0378-7753(88)80032-6.

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30

Regan, E., T. Groutso, J. B. Metson, R. Steiner, B. Ammundsen, D. Hassell, and P. Pickering. "Surface and bulk composition of lithium manganese oxides." Surface and Interface Analysis 27, no. 12 (December 1999): 1064–68. http://dx.doi.org/10.1002/(sici)1096-9918(199912)27:12<1064::aid-sia676>3.0.co;2-s.

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31

Wachs, Israel E., and Kamalakanta Routray. "ChemInform Abstract: Catalysis Science of Bulk Mixed Oxides." ChemInform 43, no. 32 (July 12, 2012): no. http://dx.doi.org/10.1002/chin.201232230.

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32

Uršič, Hana, Matej Šadl, Uroš Prah, and Val Fišinger. "Magnetic Force Microscopy of Multiferroic Bulk Ceramic Oxides." Crystals 13, no. 5 (May 19, 2023): 838. http://dx.doi.org/10.3390/cryst13050838.

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Bulk multiferroic ceramics have been extensively studied due to their great potential for magneto-electric coupling applications such as low-power and multifunctional nano-electronic devices. In most of these studies the macroscopic magnetic performance was investigated, while the magnetic response on the micro- and nano-scale was not examined in detail. Local magnetic phenomena can be studied using magnetic force microscopy (MFM), a technique derived from atomic force microscopy. MFM measures the magnetic force between the magnetised tip and the magnetic sample. It is one of the most used methods to characterise the structure of ferromagnetic domains, because the sample preparation is simple, non-destructive and provides a relatively high-resolution image. In this review paper we focus on the MFM analyses of bulk multiferroic ceramics. The core of the article is divided into four sections: the introduction, the preparation of samples prior to MFM examination, the reviews of MFM analyses performed on bulk multiferroic ceramics with and without external magnetic fields, and finally the conclusions and an outlook for the future.

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33

Fang, Qian Feng, T. Liu, Chun Li, X. P. Wang, and G. G. Zhang. "Damping Mechanisms in Oxide Materials and Their Potential Applications." Key Engineering Materials 319 (September 2006): 167–72. http://dx.doi.org/10.4028/www.scientific.net/kem.319.167.

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In this paper, we review the damping mechanisms in oxide materials, such as the short-range jump of oxygen vacancies and cation vacancies, movement of domain walls, and grain boundary sliding. Some examples in doped ZrO2, La2CuO4+δ, La2Mo2O9 and other oxide materials are briefly discussed, in which the damping capacity can reach as high as 30%. These oxides could be possibly applied as high damping materials either in the form of bulk components, or as additives in composites, or as hard damping coatings. In the last two potential applications, the high hardness and strength as well as high damping capacity of the oxides are simultaneously exploited, which cannot be realized by the usual high-damping metals and alloys.

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34

Swallow, Jessica G., Mostafa Youssef, and Krystyn J. Van Vliet. "Defect-Mediated Mechanics in Non-Stoichiometric Oxide Films." MRS Advances 3, no. 10 (2018): 537–45. http://dx.doi.org/10.1557/adv.2018.9.

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ABSTRACTChemomechanical coupling is a hallmark of the functional oxides that are used widely for energy conversion and storage applications including solid oxide fuel cells (SOFCs). These oxides rely on the presence of oxygen vacancies to enable important properties including ionic conductivity and gas exchange reactivity. However, such defects can also facilitate chemical expansion, or coupling between material volume and defect content. Such chemomechanical coupling is particularly relevant with the recent interest in thin film SOFCs which have the potential to decrease operating temperatures and enable portable applications. Thin films present a particular challenge for modelling, as experimental results indicate that film defect chemistry can differ significantly from bulk counterparts under the same experimental conditions. In this study, we explore the influence of point defects, including oxygen vacancies and cation dopants, on the elastic properties of a model material, PrxCe1-xO2-δ (PCO), using density functional theory (DFT + U) simulations. Previously, we showed that PCO films exhibit a decrease in Young’s elastic modulus E due to chemical expansion, but that this decrease can be larger than predicted based on bulk defect models. Here, we apply DFT + U to show that the biaxial elastic modulus of PCO decreases with increased oxygen vacancy content in both bulk and membrane forms. We consider the relative influences of oxygen vacancies and cation dopants on this trend, and highlight local structural changes in the presence of such defects. By relating our computational and experimental results, we evaluate the relative importance of increased oxygen vacancy content and finite thickness on the mechanical properties of oxides that are subject to chemical expansion under operando conditions. This work informs the design of μ-SOFCs, emphasizing the need to characterize thin films separately from bulk counterparts and demonstrating how functional defect content can influence development of stress and strain in devices by changing both material volume and elastic properties.

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Patra, Shanti Gopal, and Dan Meyerstein. "On the Mechanism of Heterogeneous Water Oxidation Catalysis: A Theoretical Perspective." Inorganics 10, no. 11 (October 26, 2022): 182. http://dx.doi.org/10.3390/inorganics10110182.

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Earth abundant transition metal oxides are low-cost promising catalysts for the oxygen evolution reaction (OER). Many transition metal oxides have shown higher OER activity than the noble metal oxides (RuO2 and IrO2). Many experimental and theoretical studies have been performed to understand the mechanism of OER. In this review article we have considered four earth abundant transition metal oxides, namely, titanium oxide (TiO2), manganese oxide/hydroxide (MnOx/MnOOH), cobalt oxide/hydroxide (CoOx/CoOOH), and nickel oxide/hydroxide (NiOx/NiOOH). The OER mechanism on three polymorphs of TiO2: TiO2 rutile (110), anatase (101), and brookite (210) are summarized. It is discussed that the surface peroxo O* intermediates formation required a smaller activation barrier compared to the dangling O* intermediates. Manganese-based oxide material CaMn4O5 is the active site of photosystem II where OER takes place in nature. The commonly known polymorphs of MnO2; α- (tetragonal), β- (tetragonal), and δ-(triclinic) are discussed for their OER activity. The electrochemical activity of electrochemically synthesized induced layer δ-MnO2 (EI-δ-MnO2) materials is discussed in comparison to precious metal oxides (Ir/RuOx). Hydrothermally synthesized α-MnO2 shows higher activity than δ-MnO2. The OER activity of different bulk oxide phases: (a) Mn3O4(001), (b) Mn2O3(110), and (c) MnO2(110) are comparatively discussed. Different crystalline phases of CoOOH and NiOOH are discussed considering different surfaces for the catalytic activity. In some cases, the effects of doping with other metals (e.g., doping of Fe to NiOOH) are discussed.

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Bosch, Julian, Katja Heister, Thilo Hofmann, and Rainer U. Meckenstock. "Nanosized Iron Oxide Colloids Strongly Enhance Microbial Iron Reduction." Applied and Environmental Microbiology 76, no. 1 (November 13, 2009): 184–89. http://dx.doi.org/10.1128/aem.00417-09.

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ABSTRACT Microbial iron reduction is considered to be a significant subsurface process. The rate-limiting bioavailability of the insoluble iron oxyhydroxides, however, is a topic for debate. Surface area and mineral structure are recognized as crucial parameters for microbial reduction rates of bulk, macroaggregate iron minerals. However, a significant fraction of iron oxide minerals in the subsurface is supposed to be present as nanosized colloids. We therefore studied the role of colloidal iron oxides in microbial iron reduction. In batch growth experiments with Geobacter sulfurreducens, colloids of ferrihydrite (hydrodynamic diameter, 336 nm), hematite (123 nm), goethite (157 nm), and akaganeite (64 nm) were added as electron acceptors. The colloidal iron oxides were reduced up to 2 orders of magnitude more rapidly (up to 1,255 pmol h− 1 cell− 1) than bulk macroaggregates of the same iron phases (6 to 70 pmol h− 1 cell− 1). The increased reactivity was not only due to the large surface areas of the colloidal aggregates but also was due to a higher reactivity per unit surface. We hypothesize that this can be attributed to the high bioavailability of the nanosized aggregates and their colloidal suspension. Furthermore, a strong enhancement of reduction rates of bulk ferrihydrite was observed when nanosized ferrihydrite aggregates were added.

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Li, Hongjun, and Elmer A. Ogryzlo. "Monitoring of the formation and removal of bulk, surface, and interfacial carrier traps on silicon(100)." Canadian Journal of Physics 74, S1 (December 1, 1996): 233–38. http://dx.doi.org/10.1139/p96-865.

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An RF probe was used to monitor the steady-state photo-generated carrier concentration in silicon with and without an oxide layer. The changes in this steady-state concentration during exposure to gaseous molecular and atomic species such as He, H2, O2, H, and O at temperatures between 25 and 450 °C are interpreted in terms of changes in the bulk silicon, interface, and exposed surface. The initial experiments established the relationship between the carrier concentration and the RF-probe signal, and distinguished between changes in the bulk, and on silicon surfaces and interfaces. It was found that in the case of hydrogen, bulk passivation and depassivation by H2 can be observed only at elevated temperatures, with or without an oxide layer. H-atom depassivation can be observed at all temperatures and is irreversible at room temperature. The formation of an oxide layer by exposure to O atoms at 25 and 450 °C was followed, and the oxides formed were then treated in an attempt to create an SiO2/Si interface with an acceptable density of interfacial states.

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38

Lee, S. T., Y. F. Zhang, N. Wang, Y. H. Tang, I. Bello, C. S. Lee, and Y. W. Chung. "Semiconductor nanowires from oxides." Journal of Materials Research 14, no. 12 (December 1999): 4503–7. http://dx.doi.org/10.1557/jmr.1999.0611.

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Highly pure, ultralong, and uniform-sized semiconductor nanowires in bulk quantity were synthesized by thermal evaporation or laser ablation of semiconductor powders mixed with oxides. Transmission electron microscopy study shows that decomposition of semiconductor suboxides and defect structures play important roles in enhancing the formation and growth of high-quality nanowires. A new growth mechanism is proposed on the basis of microstructure and different morphologies of the nanowires observed.

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Brockway, Molly C., and Jack L. Skinner. "Variable Phase and Electrochemical Capacitance of Electrospun MnOx Fibers Via Controlled Calcination." MRS Advances 4, no. 44-45 (2019): 2383–90. http://dx.doi.org/10.1557/adv.2019.293.

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ABSTRACTSupercapacitors have the potential to complement or replace batteries in many current and emerging applications. As inexpensive and environmentally benign capacitive materials, manganese oxides are promising electrode materials. Nanostructured oxides have high energy storage capacities owing to their increased surface-area-to-volume ratios as compared to bulk materials. By electrospinning precursor-containing polymer fibers and subsequently calcining, nanostructured MnOx fibers can be prepared with relative ease. Controlling calcination pressure and time provides a route for variable capacitance via modifying surface roughness and oxide phase. At moderate pressures and short calcination times, mixed-phase Mn2O3/Mn3O4 fibers with high surface roughness exhibit enhanced electrochemical specific capacitance.

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Chepak-Gizbrekht, M. V., and A. G. Knyazeva. "Grain boundary diffusion effect on Ti3Al alloy oxidation." Izvestiya vysshikh uchebnykh zavedenii. Fizika, no. 7 (2022): 62–68. http://dx.doi.org/10.17223/00213411/65/7/62.

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The paper presents a model of grain-boundary diffusion, supplemented by the equations of oxide formation kinetics. Conditions are considered isothermal. The alloy material in the model is represented by alternating intermetallic grains with a clear selection of triple junctions between them. Diffusion and kinetic properties of grains and boundaries may differ. The model is used to describe the process of an intermetallic alloy oxidation in bulk and along grain boundaries. The distributions of the concentrations of elements and oxides, and the change in the average integral concentrations of oxides were studied with varying reaction rate constants in the grains and in the vicinity of the boundaries.

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Soon, Aloysius, Mira Todorova, Bernard Delley, and Catherine Stampfl. "Surface oxides of the oxygen–copper system: Precursors to the bulk oxide phase?" Surface Science 601, no. 24 (December 2007): 5809–13. http://dx.doi.org/10.1016/j.susc.2007.06.062.

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Li, Haoyang, Yue Zhou, Zhihao Liang, Honglong Ning, Xiao Fu, Zhuohui Xu, Tian Qiu, Wei Xu, Rihui Yao, and Junbiao Peng. "High-Entropy Oxides: Advanced Research on Electrical Properties." Coatings 11, no. 6 (May 24, 2021): 628. http://dx.doi.org/10.3390/coatings11060628.

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The concept of “high entropy” was first proposed while exploring the unknown center of the metal alloy phase diagram, and then expanded to oxides. The colossal dielectric constant found on the bulk high-entropy oxides (HEOs) reveals the potential application of the high-entropy oxides in the dielectric aspects. Despite the fact that known HEO thin films have not been reported in the field of dielectric properties so far, with the high-entropy effects and theoretical guidance of high entropy, it is predictable that they will be discovered. Currently, researchers are verifying that appropriately increasing the oxygen content in the oxide, raising the temperature and raising the pressure during preparation have an obvious influence on thin films’ resistivity, which may be the guidance on obtaining an HEO film large dielectric constant. Finally, it could composite a metal–insulator–metal capacitor, and contribute to sensors and energy storage devices’ development; alternatively, it could be put into application in emerging thin-film transistor technologies, such as those based on amorphous metal oxide semiconductors, semiconducting carbon nanotubes, and organic semiconductors.

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Abubakar, Muazu, Ayyankalai Muthuraja, Dipen Kumar Rajak, Norhayati Ahmad, Catalin I. Pruncu, Luciano Lamberti, and Ashwini Kumar. "Influence of Firing Temperature on the Physical, Thermal and Microstructural Properties of Kankara Kaolin Clay: A Preliminary Investigation." Materials 13, no. 8 (April 16, 2020): 1872. http://dx.doi.org/10.3390/ma13081872.

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In this study, natural deposits of Kankara kaolin clay were collected and investigated in order to determine physical, microstructural, thermal, and firing properties and assess clay’s suitability as starting material for various ceramic applications. Chemical analysis of the clay was performed using XRF. Mineralogical analysis and thermal analysis of the clay were conducted using XRD and thermogravimetric thermal analysis (TGA)/differential thermal analysis (DTA), respectively. In order to assess its ceramic behavior, the clay was fired at 900–1200 °C. Maturation characteristics of fired ceramics were assessed by measuring bulk density, apparent porosity, and shrinkage. It was found that main oxides in the clay are alumina, silica, and potassium oxide, while other oxides are present in trace quantities. Kaolinite, quartz, and illite are the phases found from the XRD results, while mullite ceramic phase formed at firing temperature above 1100 °C. Maturation tests showed that ceramic properties such as bulk density and shrinkage increase with temperature, while apparent porosity decreases with temperature. The results presented in this study prove that the clay is an appropriate material for producing traditional ceramics.

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Dupuy, Alexander D., Mohammed Reda Chellali, Horst Hahn, and Julie M. Schoenung. "Multiscale phase homogeneity in bulk nanocrystalline high entropy oxides." Journal of the European Ceramic Society 41, no. 9 (August 2021): 4850–58. http://dx.doi.org/10.1016/j.jeurceramsoc.2021.03.035.

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Porta, Piero, Maria Cristina Campa, Giuseppe Fierro, Mariano Lo Jacono, Giuliano Minelli, Giuliano Moretti, and Luisa Stoppa. "Cuo–ZnO–Al2O3mixed oxides: preparation, bulk and surface characterization." J. Mater. Chem. 3, no. 5 (1993): 505–11. http://dx.doi.org/10.1039/jm9930300505.

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Shoko, E., M. F. Smith, and Ross H. McKenzie. "Charge distribution near bulk oxygen vacancies in cerium oxides." Journal of Physics: Condensed Matter 22, no. 22 (May 21, 2010): 223201. http://dx.doi.org/10.1088/0953-8984/22/22/223201.

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Ismagilov, Zinfer R., Svetlana V. Lazareva, Nadezhda V. Shikina, Vadim V. Kuznetsov, Mikhail A. Kerzhentsev, Yurii V. Ostrovsky, Nina A. Rudina, Vladimir A. Rogov, and Vladimir A. Ushakov. "Preparation and characterization of bulk uranium oxides for catalysis." Mendeleev Communications 21, no. 4 (July 2011): 209–11. http://dx.doi.org/10.1016/j.mencom.2011.07.013.

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Shaikh, Shahid, Kathleen Bethke, and Edouard Mamedov. "Propane ammoxidation on bulk, diluted and supported VSb oxides." Topics in Catalysis 38, no. 4 (August 2006): 241–49. http://dx.doi.org/10.1007/s11244-006-0022-9.

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Medvedeva, J. E., and A. J. Freeman. "Hopping versus bulk conductivity in transparent oxides: 12CaO∙7Al2O3." Applied Physics Letters 85, no. 6 (August 9, 2004): 955–57. http://dx.doi.org/10.1063/1.1781362.

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Tikhonov, V. V., D. A. Boyarskii, and O. N. Polyakova. "Investigation of microwave optical constants of bulk iron oxides." Advances in Space Research 62, no. 9 (November 2018): 2692–700. http://dx.doi.org/10.1016/j.asr.2018.07.014.

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