Journal articles: 'Metallic oxides'

1

Kallumottakkal, Muhammed, Mousa I. Hussein, Yousef Haik, and Tarik Bin Abdul Latef. "Functionalized-CNT Polymer Composite for Microwave and Electromagnetic Shielding." Polymers 13, no. 22 (November 12, 2021): 3907. http://dx.doi.org/10.3390/polym13223907.

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In this research work, we studied the microwave properties of multi-wall carbon nanotube (MWCNT) surface functionalized with metallic oxides composites. Three different concentrations (5%, 10%, and 20%) of metallic oxides were used, namely cobalt, iron, and cobalt ferrite. The surface-decorated CNTS were impregnated into polyurethane (PU) matrix. The surface-decorated MWCNTs and the MWCNTs-PU composites were characterized using electron microscopy. The dielectric properties of the samples are studied using an open-ended coaxial probe technique in a wide frequency range of (5–50 GHz). The metallic oxide-decorated surface MWCNTs-PU composites demonstrated different microwave-frequency absorption characteristics depending on the concentration of the metallic oxides.

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Park, Ki Beom, Julien O. Fadonougbo, Jong-Seong Bae, Gyu Byeong Kang, Jong In Choi, Young Do Kim, Tae-Wook Na, and Hyung-Ki Park. "The Evolution of Surface Oxides during TiFe0.9M0.1 (M = Ni, Mn) Activation: An In Situ XPS Investigation." Metals 12, no. 12 (December 6, 2022): 2093. http://dx.doi.org/10.3390/met12122093.

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The nature of TiFe-based surface oxides and their evolution during conventional activation heat treatment were investigated in this study. The as-prepared TiFe alloy was found to possess an initial composite Ti and Fe amorphous surface oxide layer of about 6 nm. Depth profiling has shown that oxides steadily vanish with increasing depth, whereas metallic Fe contribution and mixed Ti oxides arise, before eventually being found in their metallic state at 7.5 nm. In situ XPS measurements, carried out to directly observe the evolution of oxides during the activation procedure, have indicated that the initial ternary oxide begins to transform to metallic Fe and mixed Ti oxides at a temperature as low as 200 °C. Consistent with the literature, the reduction of Ti oxides took a major turn at around 400 °C. Toward the end of the in situ measurements, oxygen was partially dissolved due to the limited measurement duration: TiO and metallic Fe remained beyond 400 °C. A similar overall reduction behavior was observed for the Ni- and Mn-substituted alloys, with a few subtle exceptions: Ni existed in its metallic state from 200 °C whereas Mn was reduced from Mn3+ to the Mn2+ state only beyond 400 °C due to a pronounced difference in the oxidation driving force of these two substitution metals.

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Andreev, Andrey S., Serguey F. Tikhov, Aleksey N. Salanov, Svetlana V. Cherepanova, Olga B. Lapina, Vasiliy A. Bolotov, Yuriy Yu Tanashev, Jean Baptiste d’Espinose de Lacaillerie, and Vladislav A. Sadykov. "Design of Al₂O₃/CoAlO/CoAl Porous Ceramometal for Multiple Applications as Catalytic Supports." Advanced Materials Research 702 (May 2013): 79–87. http://dx.doi.org/10.4028/www.scientific.net/amr.702.79.

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Porous ceramometal Al2O3/CoAlO/CoAl was studied by set of physicochemical techniques such as XRD, SEM, internal field59Co and27Al MAS NMR, and porosity measurements. They revealed the cermet containing three parts. First, cobalt-free large porous alumina particles which surrounded by the second oxide part representing spinel CoxAl3-xO4(x=1,2,3) oxides. And third, oxygen-free metallic part consists of cobalt metal particles covered by Co-Al oxide protecting the metallic part from oxidation. Porosity measurements ascertained high porosity (60%) and good SSA (122 m2/g). Also the enhanced adsorption of microwaves due to metallic particles randomly distributed in oxides was found.

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Coey, J. M. D., and C. L. Chien. "Half-Metallic Ferromagnetic Oxides." MRS Bulletin 28, no. 10 (October 2003): 720–24. http://dx.doi.org/10.1557/mrs2003.212.

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AbstractHalf-metals are unusual ferromagnets that have electrons at the Fermi level in a single spin state, either spin up or spin down. Of potential interest as sources and analyzers of polarized electrons in spintronic devices, they are usually identified from spin-dependent band-structure calculations. We present a classification scheme for half-metals and then discuss methods for measuring spin polarization based on point contacts or tunnel junctions with ferromagnetic or superconducting counter electrodes. Oxide examples include CrO2, the best-studied half-metal. The half-metallicity tends to be destroyed by increasing temperature and by structural defects. The half-metals that currently offer the best prospects for spintronics applications are those with the highest Curie temperatures, such as magnetite, Fe3O4, and perhaps oxide semiconductors such as Co-doped ZnO.

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Benhaliliba, Mostefa. "Nanostructured Metallic Oxides Coating." Journal of New Technology and Materials 4, no. 1 (2014): 11–14. http://dx.doi.org/10.12816/0010289.

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Guo, Xueying, Qianqian Wang, Qiongyu Lai, Qiran Ouyang, Peng Li, Hai-Dong Yu, and Wei Huang. "Biomass-Templated Fabrication of Metallic Materials for Photocatalytic and Bactericidal Applications." Materials 12, no. 8 (April 18, 2019): 1271. http://dx.doi.org/10.3390/ma12081271.

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In this paper, we report a simple, feasible and low-cost method to fabricate self-standing metallic materials using cellulose-based biomass as sacrificial templates. This process involves the impregnation of metallic precursors to the cellulose fibers of biomass templates and the transformation of the precursors to corresponding metals or metal oxides (as well as the removal of the cellulose framework) at an elevated temperature. The structures of the metallic materials as fabricated take the form of architectures of biomass templates (e.g., chromatography paper, medical absorbent cotton, catkins of reed, seed balls of oriental plane, and petals of peach blossom), and the various kinds of metals and metal oxides fabricated with these templates include silver, gold, anatase, cupric oxide, zinc oxide, etc. We have demonstrated photocatalytic and bactericidal applications of such metallic materials, and they should find more applications in electronics, catalysis, energy storage, biomedicine and so on.

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Lungu, Mihail, Cornel Staicu, Flaviu Baiasu, Alexandru Marin, Bogdan Butoi, Daniel Cristea, Oana Gloria Pompilian, Claudiu Locovei, and Corneliu Porosnicu. "Deposition, Morphological, and Mechanical Evaluation of W and Be-Al2O3 and Er2O3 Co-Sputtered Films in Comparison with Pure Oxides." Coatings 11, no. 11 (November 22, 2021): 1430. http://dx.doi.org/10.3390/coatings11111430.

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Compact and defect-free high melting point oxide strengthened metallic matrix configurations are promising to resolve the hydrogen permeation and brittleness issues relevant to the fusion research community. Previous studies on oxide addition to metallic matrix demonstrated a mitigation in brittleness behavior, while deposition techniques and material configurations are still to be investigated. Thus, here, we report the structural, morphological, and mechanical characterization of metal-oxides thin layers co-deposited by radio frequency (RF)and direct current (DC) magnetron sputtering. A total of six configurations were deposited such as single thin layers of oxides (Al2O3, Er2O3) and co-deposition configurations as metal-oxides (W, Be)—(Al2O3, Er2O3). The study of films roughness by atomic force microscopy (AFM) method show that for Al2O3 metallic-oxides is increased to an extent that could favor gaseous trapping, while co-depositions with Be seem to promote an increased roughness and defects formation probability compared to W co-depositions. Lower elastic modulus on metal-oxide co-depositions was observed, while the indentation hardness increased for Be and decreased for W matrix configurations. These outputs are highly relevant for choosing the proper compact and trap-free configuration that could be categorized as a permeation barrier for hydrogen and furtherly studied in laborious permeation yield campaigns.

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Memarzadeh, K., M. Vargas, Jie Huang, J. Fan, and R. P. Allaker. "Nano Metallic-Oxides as Antimicrobials for Implant Coatings." Key Engineering Materials 493-494 (October 2011): 489–94. http://dx.doi.org/10.4028/www.scientific.net/kem.493-494.489.

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The use of metallic nanoparticles in the field of orthopaedics as antimicrobial components of coatings is receiving particular attention. An innovative approach has been developed whereby various metal/metal oxide nanoparticles are used to prevent infection occurring on the surface of prostheses. In this study nano metallic oxides (zinc oxide - ZnO and tungsten oxide - WO3) were used. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values of each nanoparticulate were determined against four species of bacteria (Staphylococcus aureus, Escherichia coli, Staphylococcus epidermidis and Pseudomonas aeruginosa). Subsequently the nanoparticles were prepared in a suspension of ethanol and sprayed onto the surface of glass using electrohydrodynamic deposition. Quantitative assessments as regards the antimicrobial properties of these coated samples were carried out. Comparisons of the antibacterial properties demonstrated that 2500 µg/ml or above of the oxides were required to kill the species of bacteria tested. WO3 was the most effective oxide tested in suspension using growth inhibition tests. However, coated samples demonstrated that ZnO was more bactericidal than WO3 under these conditions.

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Abdel Halim, K. S., M. Ramadan, A. Shawabkeh, and A. S. Alghamdi. "Thermal Techniques for the Production of Fe-M Alloys." Applied Mechanics and Materials 826 (February 2016): 105–10. http://dx.doi.org/10.4028/www.scientific.net/amm.826.105.

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The present manuscript is designed to investigate the possibility of manufacturing iron-metal alloys (Fe-M) via thermal techniques. These techniques are mainly depends on simultaneous reduction-sintering reactions of metal oxides. The reduction of metal oxides is an important property in metallurgical processes. It can be applied to M-Fe-O systems and also is used to develop inter-metallic alloys with specific properties. The produced metallic materials have wide range of applications and are characterized by unique physical and mechanical properties. The composition of the produced alloys is often a key element in optimizing their properties. Iron oxide doped another metal oxide such as nickel oxide is used as starting materials to produce metallic materials containing iron contaminated with nickel metal using thermal techniques. The sintering-reduction reactions of the composite oxide materials are investigated under different operation conditions. The experimental results show that the reduction-sintering thermal techniques are economic and promising routes for the production of different Fe-M alloys. The different factors affecting the rate of reduction such as temperature and ratio of doping materials are investigated. The results obtained are used to demonstrate the kinetics and mechanisms of reduction of metal oxides.

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10

Reischel, Michael T. "Metallic oxides as Freezing Nuclei." Journal of Weather Modification 10, no. 1 (April 3, 2018): 97–106. http://dx.doi.org/10.54782/jwm.v10i1.595.

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The extent to which metallic oxides may be active in ice nucleation processes is of considerable interest since metallic oxides are of common natural occurrence and are also produced during many combustion processes....... The tests conducted indicate that in general the metallic oxides are not characterized by a high level of activity as freezing nuclei although a few do exhibit moderate activity.......

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11

Farrah, S. R., and D. R. Preston. "Adsorption of Viruses by Diatomaceous Earth Coated with Metallic Oxides and Metallic Peroxides." Water Science and Technology 24, no. 2 (July 1, 1991): 235–40. http://dx.doi.org/10.2166/wst.1991.0065.

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Diatomaceous earth coated with oxides of aluminium, calcium, iron, magnesium, or manganese were not found to be useful for recovering viruses from water. The oxide coatings were not stable in water or only adsorbed viruses in small volumes of water. Further modification of coatings of magnesium oxide to make magnesium peroxide produced a modified diatomaceous earth that efficiently adsorbed viruses in water. Filters containing 3.5 g of diatomaceous earth adsorbed an average of greater than 90% of MS2, polio 1, coxsackie B5, and echo 5 in tapwater at approximately pH 8.5, even after 100 liters of tapwater had passed through the filters. From 15 to 40% of MS2 or enteroviruses could be recovered from tapwater using filters containing diatomaceous earth coated with magnesium peroxide.

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12

Kawazoe, Hiroshi, Hiroshi Yanagi, Kazushige Ueda, and Hideo Hosono. "Transparent p-Type Conducting Oxides: Design and Fabrication of p-n Heterojunctions." MRS Bulletin 25, no. 8 (August 2000): 28–36. http://dx.doi.org/10.1557/mrs2000.148.

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Inorganic solids with wide bandgaps are usually classified as electrical insulators and are used in industry as insulators, dielectrics, and optical materials. Many metallic oxides have wide bandgaps because of the significant contribution of ionic character to the chemical bonds between metallic cations and oxide ions. Their ionic nature simultaneously suppresses the formation of easily ionizable shallow donors or acceptors and enhances the localization of electrons and positive holes. Thus it is understandable that interest in these wide-gap oxides as conductive materials has not been strong.

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13

Zarzycki, Arkadiusz, Juliusz Chojenka, Marcin Perzanowski, and Marta Marszalek. "Electrical Transport and Magnetic Properties of Metal/Metal Oxide/Metal Junctions Based on Anodized Metal Oxides." Materials 14, no. 9 (May 4, 2021): 2390. http://dx.doi.org/10.3390/ma14092390.

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In this paper, we describe magnetoelectric properties of metal/metal-oxide/metal junctions based on anodized metal oxides. Specifically, we use Ti and Fe metallic layers separated by the porous metal-oxides of iron or titanium formed by the anodization method. Thus, we prepare double junctions with at least one ferromagnetic layer and measure magnetoresistance, as well as their current-voltage and magnetic characteristics. We find that magnetoresistance depends on that junction composition and discuss the nature of differential resistance calculated from I-V characteristics. Our findings show that a top metallic layer and the interface between this layer and anodized oxide, where strong interatomic diffusion is expected, have the strongest influence on this observed behavior.

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14

Sato,, Norio. "Surface Oxides Affecting Metallic Corrosion." Corrosion Reviews 19, no. 3-4 (August 2001): 253–72. http://dx.doi.org/10.1515/corrrev.2001.19.3-4.253.

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Szotek, Z., W. M. Temmerman, A. Svane, L. Petit, G. M. Stocks, and H. Winter. "Half-metallic transition metal oxides." Journal of Magnetism and Magnetic Materials 272-276 (May 2004): 1816–17. http://dx.doi.org/10.1016/j.jmmm.2003.12.818.

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16

Rao, C. N. R. "Virtues of marginally metallic oxides." Chemical Communications, no. 19 (1996): 2217. http://dx.doi.org/10.1039/cc9960002217.

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Du, Hongying, Andrey Karasev, Olle Sundqvist, and Pär Jönsson. "Modification of Non-Metallic Inclusions in Stainless Steel by Addition of CaSi." Metals 9, no. 1 (January 12, 2019): 74. http://dx.doi.org/10.3390/met9010074.

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The focus of this study involved comparative investigations of non-metallic inclusions in 316L stainless steel bars without and with Ca treatments. The inclusions were extracted by using electrolytic extraction (EE). After that, the characteristics of the inclusions, such as morphology, size, number, and composition, were investigated by using a scanning electron microscope (SEM) in combination with an energy dispersive X-ray spectroscopy (EDS). The following four types of inclusions were observed in 316L steels: (1) Elongated MnS (Type I), (2) MnS with hard oxide cores (Type II), (3) Undeformed irregular oxides (Type III), and (4) Elongated oxides with a hard oxide core (Type IV). In the reference sample, only a small amount of the Type III oxides (Al2O3–MgO–MnO–TiOx) existed. However, in Ca-treated 316L steel, about 46% of the observed inclusions were oxide inclusions (Types III and IV) correlated to gehlenite and to a mixture of gehlenite and anorthite, which are favorable for the machinability of steel. Furthermore, untransformed oxide cores (Al2O3–MgO–MnO) were also found in the inclusions of Type IV. The mechanism leading to different morphologies of oxide inclusions is also discussed.

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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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Belov, B., A. Trotsan, and O. Vlasova. "THE ANALYSIS OF STRUCTURE-CHEMICAL STATE OF DUPLEX SYSTEM OF SILICATES-SILICIDES OF ALKALINE EARTH METALS." Casting processes 150, no. 4 (December 1, 2022): 3–12. http://dx.doi.org/10.15407/plit2022.04.003.

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The classification and structuring of oxide and metallic phases of binary duplex systems of silicates-silicides of alkaline earth metals are carried out in the work. This will determine the optimal composition of alkaline earth metal alloys based on silicon in the refining of ferrocarbon melts and modification of non-metallic inclusions. The ionic-molecular complexes of magnesium, oxygen and silicon are constructed in the work, which determine the mechanism of formation of non-metallic inclusions (magnesium silicates) in steel when using silicomagnesium alloys for refining. The parameters of chemical bonding for oxides with ionic bond type, for liquid silicomagnesium alloys having a metallic type of chemical bonding and for hard alloys with metal-covalent bond are determined. The presented results of structural and chemical analysis of the duplex system MgO–SIO2–Mg–Si allow to reveal the mechanisms of desulfurization processes and to develop technologies of blast furnace desulfurization in smelting and ladle treatment with furnace slag, magnesium and its alloys with silicon. Keywords: polygonal diagram, magnesium oxides, alkaline earth metal silicides, quantum mechanical parameters, classification and structuring.

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Jarosz-Wilkołazka, Anna, and Marcin Grąz. "Organic acids production by white rot Basidiomycetes in the presence of metallic oxides." Canadian Journal of Microbiology 52, no. 8 (August 1, 2006): 779–85. http://dx.doi.org/10.1139/w06-032.

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The purpose of the present work was to determine if selected fungal strains belonging to wood-rotting Basidiomycetes are able to grow on and to solubilize different insoluble oxides in solid media. Twenty-eight strains of white rot fungi were checked for their growth on oxide-amended media (ZnO, CaO, Cu2O). All strains displayed growth on Zn-amended plates but to a different extent, and Cu2O-amended plates turned out to be the most toxic oxide. Most of the tested strains solubilized oxalates and produced noticeable clear zones under the mycelium. These clear zones were tested for the presence of organic acids, the level of which was clearly elevated upon exposure of fungal strains to insoluble oxides. We determined the presence of oxalic, malic, and formic acids, with oxalic acid the predominant one.Key words: metal oxalates, oxalic acid, insoluble oxides, wood-rotting fungi.

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Kupková, Miriam, Martin Kupka, Renáta Oriňáková, and Radka Gorejová. "Microstructure, Stiffness and Corrosion of Bare and Phosphated Specimens Made by Sintering of Structured Iron-Iron Oxide Spheres." Defect and Diffusion Forum 405 (November 2020): 411–16. http://dx.doi.org/10.4028/www.scientific.net/ddf.405.411.

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Granulated iron oxide particles were incompletely reduced to structured particles comprised metallic iron and residual iron oxides. Structured particles were pressed into prismatic compacts and sintered. Some of sintered specimens were subsequently phosphatized and calcined. Specimens with an iron phosphate coating were found stiffer than specimens without coating. In Hanks' solution, a galvanic corrosion was induced by more noble iron oxides coupled to a less noble metallic iron. This could explain higher corrosion potentials and higher rates of iron dissolution in comparison with a pure iron. The coating of specimens with iron phosphates shifted corrosion potentials towards more negative values and slowed down the dissolution of iron. This was most likely caused by a reduction in oxygen flow through the coating to iron-oxide cathodes, which has enhanced the influence of diffusion control on the kinetics of reduction reaction.

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Shirzadi, A. A., and E. R. Wallach. "Novel Method for Diffusion Bonding Superalloys and Aluminium Alloys (USA Patent 6,669,534 B2, European Patent Pending)." Materials Science Forum 502 (December 2005): 431–36. http://dx.doi.org/10.4028/www.scientific.net/msf.502.431.

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A novel method for diffusion bonding metallic alloys with stable surface oxide films (e.g. nickel and cobalt base superalloys and aluminium alloys) has been developed. The stable oxides on the faying surfaces of these alloys are replaced, prior to the bonding process, with a very thin metallic layer and/or less stable oxides, using a proprietary non-chemical oxide removal method based on the use of gallium. This new method is very rapid and neither requires the use of any sophisticated equipment nor is a costly process. Bonding is then readily achieved by either solid-state or transient-liquid-phase (TLP) diffusion bonding. Using this method, bonds in nickelbase and cobalt-base superalloys with “virtually invisible” bond interfaces and bonds in aluminium alloys with strengths as high as those of the parent alloys can be produced.

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23

Ocal, C., S. Ferrer, and N. García. "Diffusion of metallic atoms through thin oxides in metallic substrates." Surface Science Letters 162, no. 1-3 (October 1985): A603. http://dx.doi.org/10.1016/0167-2584(85)90305-6.

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Ocal, C., S. Ferrer, and N. García. "Diffusion of metallic atoms through thin oxides in metallic substrates." Surface Science 162, no. 1-3 (October 1985): 558–62. http://dx.doi.org/10.1016/0039-6028(85)90948-3.

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Cardenia, Chiara, Efthymios Balomenos, Pritii Wai Yin Tam, and Dimitrios Panias. "A Combined Soda Sintering and Microwave Reductive Roasting Process of Bauxite Residue for Iron Recovery." Minerals 11, no. 2 (February 22, 2021): 222. http://dx.doi.org/10.3390/min11020222.

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In this study an integrated process is presented as a suitable method to transform Fe3+ oxides present in bauxite residue into magnetic oxides and metallic iron through a microwave roasting reduction, avoiding the formation of hercynite (FeAl2O4). In the first step, all the alumina phases were transformed into sodium aluminates by adding sodium carbonate as a flux to BR and then leached out through alkali-leaching to recover alumina. Subsequently, the leaching residue was mixed with carbon and roasted by using a microwave furnace at the optimum conditions. The iron oxide present in the sinter was converted into metallic iron (98%). In addition, hercynite was not detected. The produced cinder was subjected to a wet high intensity magnetic separation process to separate iron from the other elements.

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Gao, Xiaoyong, Lin Zhang, Lifeng Zhang, and Xuanhui Qu. "Non-metallic inclusions in a superalloy during refining through cold crucible levitation melting process." Metallurgical Research & Technology 119, no. 2 (2022): 207. http://dx.doi.org/10.1051/metal/2022012.

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Oxide and nitride inclusions in a Ni-based superalloy during the cold crucible levitation melting (CCLM) process were investigated towards a better understanding for the removal of inclusions from the metal. The number, morphology, size distribution and spatial distribution of inclusions were characterized using an automated scanning electron microscopy with energy-dispersive X-ray spectroscopy. Inclusions in the alloy were efficiently agglomerated and removed by floating during CCLM process. Inclusion clusters as big as 30-400 ?m were observed. Oxide clusters were efficiently floated during pouring process. The removal ratios of oxides were about 21% without pouring and 62% with pouring, respectively. Additionally, CCLM promotes the separation of oxides from nitrides. The effect of CCLM on the removal of nitride inclusions is not such evident compared with oxides. The mechanism of inclusion removal during CCLM was clarified.

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Li, X. P., M. Yan, G. Ji, and M. Qian. "Applied Pressure on Altering the Nano-Crystallization Behavior of Al86Ni6Y4.5Co2La1.5Metallic Glass Powder during Spark Plasma Sintering and Its Effect on Powder Consolidation." Journal of Nanomaterials 2013 (2013): 1–6. http://dx.doi.org/10.1155/2013/101508.

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Metallic glass powder of the composition Al86Ni6Y4.5Co2La1.5was consolidated into 10 mm diameter samples by spark plasma sintering (SPS) at different temperatures under an applied pressure of 200 MPa or 600 MPa. The heating rate and isothermal holding time were fixed at 40°C/min and 2 min, respectively. Fully dense bulk metallic glasses (BMGs) free of particle-particle interface oxides and nano-crystallization were fabricated under 600 MPa. In contrast, residual oxides were detected at particle-particle interfaces (enriched in both Al and O) when fabricated under a pressure of 200 MPa, indicating the incomplete removal of the oxide surface layers during SPS at a low pressure. Transmission electron microscopy (TEM) revealed noticeable nano-crystallization of face-centered cubic (fcc) Al close to such interfaces. Applying a high pressure played a key role in facilitating the removal of the oxide surface layers and therefore full densification of the Al86Ni6Y4.5Co2La1.5metallic glass powder without nano-crystallization. It is proposed that applied high pressure, as an external force, assisted in the breakdown of surface oxide layers that enveloped the powder particles in the early stage of sintering. This, together with the electrical discharge during SPS, may have benefitted the viscous flow of metallic glasses during sintering.

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Altamirano-Juárez, Delia Cristina. "Modulation of the Metallic Oxide Properties through of Soft Chemistry Techniques for Several Applications." Advances in Science and Technology 54 (September 2008): 337–42. http://dx.doi.org/10.4028/www.scientific.net/ast.54.337.

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Metallic oxides are widely used in the industry; these are object of intensive research due to the versatility of their applications and the possibility of modulating their properties when the techniques and the procedures of obtaining them vary. The soft chemistry technique is shown as an option to obtain films of metallic oxide for their use optoelectronic devices. This work emphasizes the importance of applying dip-coating techniques of low cost for the industry with good results.

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Su, Ya Xin, Li Ming Ren, and Wen Yi Deng. "Effect of CO/CH₄ on Redox of Iron during NO Reduction by XRD/SEM." Applied Mechanics and Materials 448-453 (October 2013): 559–63. http://dx.doi.org/10.4028/www.scientific.net/amm.448-453.559.

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NO reduction by iron was conducted in a one-dimensional ceramic tubular reactor at 300 - 1100 °C with simulated flue gas of 0.05% NO in N2base. The evolution of metallic iron was investigated by X-ray diffraction (XRD) and Scanning Electron Microscope (SEM) methods. The effect of reducing gases including CO and CH4was analyzed on the redox of iron. Results showed that metallic iron was oxidized to its oxides after the reaction with NO. In N2atmosphere, Fe3O4was the major iron oxide at 550 °C and Fe2O3was the major iron oxide at 1100 °C. SEM image of the iron sample surface showed that the iron surface was smooth and dense after the iron reduced NO at 550 °C, however, the iron surface became porous after the iron reduced NO at 1100 °C. Reducing gas CO could reduce iron oxides to metallic iron. XRD result showed that a little FeO was found but metallic iron was still the dominant component of the iron sample after the reaction with NO in CO atmosphere. CO was not effective to maintain a durable NO reduction efficiency in simulated flue gas atmosphere while CH4was very effective. XRD result of the iron sample after the 100 hours durable test at 1050°C when 1.17% CH4was added into the simulated flue gas showed that the iron was not fully oxidized during the durable reaction.

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Doval, H. J. F., O. A. Scelza, and A. A. Castro. "Methane oligomerization on supported metallic oxides." Reaction Kinetics and Catalysis Letters 34, no. 1 (March 1987): 143–48. http://dx.doi.org/10.1007/bf02069215.

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Nakajima, Hideo, and Ryusuke Nakamura. "Fabrication of Hollow Nano Particles of Metallic Oxides through Oxidation Process." Materials Science Forum 638-642 (January 2010): 67–72. http://dx.doi.org/10.4028/www.scientific.net/msf.638-642.67.

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The formation mechanisms of hollow metal oxide through the oxidation of several metal nanoparticles have been studied by transmission electron microscopy. For Zn, Al, Cu, Ni and Fe nanoparticles, hollow oxide nanoparticles were obtained as a result of vacancy aggregation in the oxidation processes. The formation of the hollow morphology is attributed to the faster outward diffusion of metal ions through the oxide layer in the oxidation processes. Further changes in morphology during the annealing of hollow Cu, Ni and Fe oxides at higher temperatures in air were examined.

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Ludwig, Bellamarie, and Taryn T. Burke. "Infrared Spectroscopy Studies of Aluminum Oxide and Metallic Aluminum Powders, Part I: Thermal Dehydration and Decomposition." Powders 1, no. 1 (March 10, 2022): 47–61. http://dx.doi.org/10.3390/powders1010005.

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In this work, we study three aluminum oxides (alpha, gamma, boehmite) and various oxidized metallic aluminum powders to observe their dehydration and decomposition behavior using in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and scanning electron microscopy (SEM). We find that a temperature increase to the aluminum oxides (aluminas) reduces physically adsorbed water molecules to reveal the presence of hydroxyl groups. All three aluminas contained bridged hydroxyls located at 3670 cm−1; we found additional surface hydroxyls, which varied based on the oxidation state of the aluminum atom. Oxidized metallic aluminum powders that were aged resulted in similar behavior; however, the results differed depending on the method of aging. We find that naturally aged aluminum (NA-Al) powders with heavy oxidation in the form of the tri-hydroxide decomposed and did not reveal any detectable surface hydroxyl peaks. When aged using artificial methods (AA-Al), we find both surface hydroxyls, including bridged hydroxyls at 3670, 3700, and 3730 cm−1, and a remaining boehmite-like surface. These results show that metallic aluminum powders can be tailored for specific applications, regardless of age. It also elucidates different ways to pre-process the powders to control the surface oxide layer, corroborated by comparison with the models oxides studied herein.

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Peng, Bin, Ren-Ci Peng, Yong-Qiang Zhang, Guohua Dong, Ziyao Zhou, Yuqing Zhou, Tao Li, et al. "Phase transition enhanced superior elasticity in freestanding single-crystalline multiferroic BiFeO3 membranes." Science Advances 6, no. 34 (August 2020): eaba5847. http://dx.doi.org/10.1126/sciadv.aba5847.

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The integration of ferroic oxide thin films into advanced flexible electronics will bring multifunctionality beyond organic and metallic materials. However, it is challenging to achieve high flexibility in single-crystalline ferroic oxides that is considerable to organic or metallic materials. Here, we demonstrate the superior flexibility of freestanding single-crystalline BiFeO3 membranes, which are typical multiferroic materials with multifunctionality. They can endure cyclic 180° folding and have good recoverability, with the maximum bending strain up to 5.42% during in situ bending under scanning electron microscopy, far beyond their bulk counterparts. Such superior elasticity mainly originates from reversible rhombohedral-tetragonal phase transition, as revealed by phase-field simulations. This study suggests a general fundamental mechanism for a variety of ferroic oxides to achieve high flexibility and to work as smart materials in flexible electronics.

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Zhang, Guangbiao, Yuanxu Wang, Zhenxiang Cheng, Yuli Yan, Chengxiao Peng, Chao Wang, and Shuai Dong. "A class of rare antiferromagnetic metallic oxides: double perovskite AMn3V4O12 (A = Na+, Ca2+, and La3+) and the site-selective doping effect." Physical Chemistry Chemical Physics 17, no. 19 (2015): 12717–21. http://dx.doi.org/10.1039/c5cp00186b.

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Halim, K. S. Abdel, A. A. El-Geassy, Mohamed Ramadan, M. I. Nasr, A. Hussein, Naglaa Fathy, and Abdulaziz S. Alghamdi. "Reduction Behavior and Characteristics of Metal Oxides in the Nanoscale." Metals 12, no. 12 (December 18, 2022): 2182. http://dx.doi.org/10.3390/met12122182.

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The development of nanomaterials and nanotechnology enables the production of nanosized metallic alloys with advanced characteristics from their oxides via a thermal reduction technique. The aim of the present work was to produce metallic iron, nickel, and tungsten through the gaseous reduction of nanosized metal oxide powders as a preliminary step towards the fabrication of nanosized heavy tungsten alloys with unique properties. Nanosized NiO, Fe2O3, and WO3 were isothermally and non-isothermally reduced with H2, and the oxygen weight loss was continuously recorded as a function of time. The Thermogravimetric TG-DTA technique was applied in the non-isothermal reduction up to 1000 °C. The reduction extents were calculated from the TG curve, whereas the accompanying heat of the reaction was measured from the DTA curve. The results revealed that NiO was reduced at <420 °C, Fe2O3 was reduced at <600 °C, and WO3 was reduced at >950 °C. In the isothermal process, metal oxides were reduced with H2 at 700–1000 °C; a micro-force balance was used and the O2 weight loss was continuously recorded. At a given temperature, the rate of reduction increased in the order NiO > Fe2O3 > WO3. The nano-oxide powders and the reduced products were physically and chemically characterized. The activation energy (Ea) values were computed from the isothermal reduction in the initial and later stages to elucidate the corresponding reduction mechanism. The Ea values indicated that the reduction of metal oxides was controlled by the gas diffusion mechanism at both the initial and later stages of reduction. The results of the present study determined the optimal operation parameters at which the thermal gaseous reduction technique could be applied for preparing metallic alloys from nanosized metal oxides.

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Chu, Chun Lin, Jian Yih Wang, Jye Lee, Ruey Yi Lee, and Shyong Lee. "Evaluation on Some Metallic Alloys for SOFC Interconnect." Materials Science Forum 544-545 (May 2007): 989–92. http://dx.doi.org/10.4028/www.scientific.net/msf.544-545.989.

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Five oxidized metallic alloys, namely, Crofer22, equivalent ZMG232, stainless steel SS430, SS304 and Inconel718 were subjected to oxidation treatment in hot air environment for various period of time. Then the resulted oxide scale was analyzed by scanning electron microscopy (SEM), electron probe micro analyzer (EPMA) and X-ray diffraction (XRD). All the five alloys contain comparable amount of Cr, Mn, Fe, and their surface oxides as analyzed indicate to be Cr2O3 and (Mn, Fe)Cr2O4 spinel compound.

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Kozyrev, N. A., I. V. Osetkovskii, A. A. Usol’tsev, E. V. Polevoi, and A. R. Mikhno. "Composition of non-metallic inclusions and microstructure of electric arc coating formed using the flux-cored wire of Fe – C – Si – Mn – Сr – Ni – Mo system." Izvestiya. Ferrous Metallurgy 65, no. 6 (June 22, 2022): 421–26. http://dx.doi.org/10.17073/0368-0797-2022-6-421-426.

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The article considers the study of composition of the non-metallic inclusions and microstructure of the electric arc coating using the flux-cored wire of Fe – C – Si – Mn – Cr – Ni – Mo system. Formation of the electric arc coating was carried out using the ASAW-1250 automatic arc welding machine by the investigated wire. In order to influence the level of contamination of the deposited metal with non-metallic oxide inclusions, aluminum gas purification dust was introduced into the flux-cored wire (instead of amorphous carbon). Composition of the electric arc coating was determined using XRF-1800 spectrometer. Microstructure of the electric arc coatings was studied by optical microscopy. The phase and elemental compositions were studied using scanning electron microscopy on MIRA 3 LMH instrument. Non-metallic inclusions in the electric arc coating consist of oxides of silicon, fluorine, calcium, aluminum and magnesium oxides. The darker component in the inclusion, which looks like rectilinear crystals directed from the surface deep into the inclusion, has a similar phase composition, but differs somewhat in the content of chemical elements. A small dark component of a rounded shape (aluminum and magnesium oxides) is observed in the inclusion. Traces of sulfur are highlighted along the contour of the globules. Metallographic analysis of the deposited surface showed that the microstructure of the deposited layer is a coarse-needle martensite. The structure is uniform, has a dendritic (columnar) structure characteristic for cast metal. The results of the conducted investigations allow measures to be developed to reduce the content of non-metallic inclusions containing elements of fluorine, sodium and aluminum, which in turn may adversely affect the physical and mechanical properties of the deposited layer, for example, by using refining additives to reduce the contamination of the deposited layer with non-metallic inclusions.

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Chmielnicka, Anna, Iwona A. Rutkowska, and Pawel J. Kulesza. "Application of Mixed-Metal-Oxides As Active Supports for Dispersed Metal Centers: Enhancement of Electrocatalytic Reduction of Carbon Dioxide." ECS Meeting Abstracts MA2022-01, no. 49 (July 7, 2022): 2085. http://dx.doi.org/10.1149/ma2022-01492085mtgabs.

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Application of metal oxides as active matrices in electrocatalysis is particular importance. The hydrous behavior, which favors proton mobility and affects overall reactivity, reflects not only the oxide’s chemical properties but its texture and morphology as well. What is of importance to electrochemical science and technology, certain nonstoichiometric mixed-valence oxides could exhibit pseudo-metallic conductivity and possess appreciable catalytic activity. For example, mixed oxide systems stabilized through Zr-O-W bonds have been demonstrated to be very attractive acid catalysts exhibiting high catalytic activities and good stabilities in many demanding industrial reactions. For electrocatalytic applications, mixed-valent tungsten(VI,V) oxide and zirconium(IV) oxide have been sequentially deposited and integrated through voltammetric potential cycling to form sub-microstructured films on glassy carbon electrode. The mixed WO3/ZrO2 systems are characterized by fast charge (electron, proton) propagation during the system’s redox transitions. By dispersing metallic copper electrocatalytic nanoparticles (generated from Cu2O) over such active WO3/ZrO2 supports, the electrocatalytic activities of the respective systems toward the reduction of oxygen or carbon dioxide have been enhanced even at decreased loadings in acid media. The enhancement effects should be attributed to features of the mixed metal oxide support such as porosity and high population of hydroxyl groups (due to presence of ZrO2), high Broensted acidity of sites formed on mixed WO3/ZrO2, fast electron transfers coupled to unimpeded proton displacements (e.g. in HxWO3), as well as strong metal-support interactions between nanosized metals (Pt or Cu) and the metal (W, Zr) oxo species. The fact that WO3/ZrO2 nanostructures are in immediate contact with the metallic catalytic sites leads to the specific interactions (via the surface hydroxyl groups) with the reaction intermediates (e.g. CO adsorbates). Mechanistic studies involving chronoamperometric, voltammetric and gas-diffusion electrode measurements are pursued, in addition to spectroscopic and XPS measurements. Results of comparative measurements, involving single components only, will be provided as well. Acknowledgements: This work was supported by the National Science Center (Poland) under Opus Project (2018/29/B/ST5/02627.

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Liyanage, Laalitha S. I., Jagoda Sławińska, Priya Gopal, Stefano Curtarolo, Marco Fornari, and Marco Buongiorno Nardelli. "High-Throughput Computational Search for Half-Metallic Oxides." Molecules 25, no. 9 (April 25, 2020): 2010. http://dx.doi.org/10.3390/molecules25092010.

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Half metals are a peculiar class of ferromagnets that have a metallic density of states at the Fermi level in one spin channel and simultaneous semiconducting or insulating properties in the opposite one. Even though they are very desirable for spintronics applications, identification of robust half-metallic materials is by no means an easy task. Because their unusual electronic structures emerge from subtleties in the hybridization of the orbitals, there is no simple rule which permits to select a priori suitable candidate materials. Here, we have conducted a high-throughput computational search for half-metallic compounds. The analysis of calculated electronic properties of thousands of materials from the inorganic crystal structure database allowed us to identify potential half metals. Remarkably, we have found over two-hundred strong half-metallic oxides; several of them have never been reported before. Considering the fact that oxides represent an important class of prospective spintronics materials, we have discussed them in further detail. In particular, they have been classified in different families based on the number of elements, structural formula, and distribution of density of states in the spin channels. We are convinced that such a framework can help to design rules for the exploration of a vaster chemical space and enable the discovery of novel half-metallic oxides with properties on demand.

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Mikhailov, Gennady G., and L. A. Makrovets. "Thermodynamic Modeling of the Processes of Interaction of Calcium, Magnesium, Aluminum and Boron with Oxygen in Metallic Melts." Materials Science Forum 946 (February 2019): 162–68. http://dx.doi.org/10.4028/www.scientific.net/msf.946.162.

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A method for calculation of the diagrams of steel deoxidation and modification by calcium, magnesium, aluminum and boron was developed. The coordinates of the liquidus surfaces of the oxide systems B2O3–Al2O3–MgO, B2O3–Al2O3–CaO, B2O3–MgO–CaO were found at 1873 K. The energy parameters were determined for the theory of subregular ionic solutions of the studied oxide systems. The coordinates of the solubility surfaces for the systems Fe–Mg–Al–B–O, Fe–Ca–Al–B–O, Fe–Mg–Ca–Al–B–O were calculated. The effect of the total pressure on solubility of magnesium and calcium in liquid iron was studied. The activity of the components of the metallic melt was calculated using the first-order interaction parameters (Wagner's theory). The activities of the components of solid solutions (oxides and spinels) were equated with their molar fractions. It was shown that during extensive refining of metal from the oxygen, only a small fraction of boron oxidizes and these oxides form fraction of the oxide melts. The major non-metallic oxide inclusions were magnesia spinel, calcium bialuminate and liquid oxide formations. The "free" boron was dissolved in liquid metal in amounts which were in equilibrium with oxide phases.

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Mentus, S., D. M. Majstorović, B. S. Tomić, and R. Dimitrijević. "Reduction of NiO-WO₃ Oxide Mixtures Synthesized by Gel-Combustion Technique: A Route to Ni-W Alloys." Materials Science Forum 494 (September 2005): 345–50. http://dx.doi.org/10.4028/www.scientific.net/msf.494.345.

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The mixtures NiO-WO3 were synthesized by the combustion of gels obtained by drying common solutions of nickel nitrate, polytungstic acid and citric acid. The X-ray diffractograms of oxide mixtures confirmed mutual interaction of oxides during synthesis leading to a new phase, NiWO4. The reduction of oxide mixtures in hydrogen atmosphere was investigated thermogravimetrically. The temperature of reduction of the oxide mixture lies between the temperatures of reduction of pure oxides and monotonously increases with the increase in WO3 mole fraction; however, the reduction itself is a multi-step process, preferably in the composition region rich in NiO. The X-ray diffractometry of metallic residues evidenced Ni-W alloys and tungsten excess to be the reduction products.

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Kanathila, Hema, Ashwin M. Pangi, Suvidha Patil, Shilpa Shirlal, and Rahul Jaiswal. "An Insight in to Various Metallic Oxide Nanoparticles as Antimicrobials and Their Applications in Dentistry." Journal of Evolution of Medical and Dental Sciences 10, no. 33 (August 16, 2021): 2803–8. http://dx.doi.org/10.14260/jemds/2021/572.

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Oral cavity contains numerous microorganisms. Among them, some are pathogenic and cause infections. Hence to control and prevent such infections, a lot of research has been conducted on different materials using various advanced techniques. Nanotechnology and nanoscience have emerged in the recent years exploring the antimicrobial effects of metal nanoparticles. Metal oxide nanoparticles have shown good results against microorganisms. Distinct physical, chemical and biologic properties of metallic oxide nanoparticles make them efficient antimicrobial agents. Both the size and high surface to volume ratio have been considered as the reason for their microbicidal efficacy. Metallic oxide nanoparticles show high durability and less cell toxicity compared to organic nanoparticles. And this positive response of metallic oxide nanoparticles make their use in medical and dental fields more promising. Most of the infections of oral cavity are fungal, bacterial or viral. In dentistry, microorganisms are believed to cause failures of many treatment by causing infections. To achieve a long-term success of treatment rendered, various possibilities have been studied. Application of this nanotechnology in dentistry termed as nano dentistry, has brought many effective changes in the control of oral infections as well as changes in the dental materials. Various metallic nanoparticles like silver nanoparticles, zinc oxide nanoparticles etc., have been used as well as modified in order to apply in dentistry. Many researches have been carried out by incorporating metallic oxide nanoparticles with dental materials which have shown excellent antimicrobial effectiveness. This review focuses on metal and metallic oxide nanoparticles and their effectiveness as antimicrobials and their various applications in dental field. KEY WORDS Nanoparticles, Antimicrobials, Metallic Oxides, Dental Materials, Dentistry

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Pham Hong, Hanh, Linh Do Chi, Phong Nguyen Ngoc, and Lam Nguyen Duc. "Synthesis and characterization of NiCoOx mixed nanocatalysts for anion exchanger membrane water electrolysis (AEMWE)." Vietnam Journal of Catalysis and Adsorption 9, no. 2 (July 31, 2020): 49–53. http://dx.doi.org/10.51316/jca.2020.028.

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Anion exchange membrane water electrolysis (AEMWE) is a well developed technology for the conversion of water into hydrogen and oxygen. AEMWE is still a developing technology. One of the major advantages of AEM water electrolysis is the replacement ofconventional noble metal electrocatalysts with low cost transition metal catalysts. In this study, we report characterization of NiCoOxmixed metallic oxides synthesized by the hydrolysis method as anodic electrocatalysts for AEMWE. The mechanisms of the thermal decomposition process of precursors to form mixed metallic oxide powders were studied by means of thermal gravity analysis (TGA), X-ray diffraction (XRD) while transmission electron microscopy (TEM) were used to evaluate the crystallographic structure, morphology and size of catalyst particles. The surface reactivity and stability of these oxides was investigated by cyclic voltammetry (CV) electrochemical method in solution of 1 M KOH. Based on the given results, the good anodic electrocatalyst was found.

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Ilinskiy A.V. and Shadrin E.B. "Patterns of formation of electrically conductive properties of oxides of the Magneli series." Physics of the Solid State 65, no. 3 (2023): 450. http://dx.doi.org/10.21883/pss.2023.03.55588.536.

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The hybridization of vanadium ions and oxygen ions is considered for four vanadium oxides included in the Magneli series: VO, V2O3, VO2, V2O5. Based on the data on hybridization, the details of the structure of the crystal lattice of these oxides are analyzed. For each oxide, the role of electrons not participating in the stabilization of the crystal frame in the process of the semiconductor-metal phase transition was revealed. The complex Mott-Peierls character of the phase transitions in all the listed strongly correlated compounds has been established. It is shown that as the degree of oxidation of the V atom increases, the numerical value of the metallic conductivity of the high-temperature phase naturally decreases and, simultaneously, the temperature of the phase transition from the semiconductor to the metallic state increases. Keywords: phase transitions, Magneli series, electron correlations, hybridization of atomic orbitals.

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Ильинский, А. В., and Е. Б. Шадрин. "Закономерности формирования электропроводящих свойств окислов ряда Магнели." Физика твердого тела 65, no. 3 (2023): 460. http://dx.doi.org/10.21883/ftt.2023.03.54746.536.

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The hybridization of vanadium ions and oxygen ions is considered for four vanadium oxides included in the Magneli series: VO, V2O3, VO2, V2O5. Based on the data on hybridization, the details of the structure of the crystal lattice of these oxides are analyzed. For each oxide, the role of electrons not participating in the stabilization of the crystal frame in the process of the semiconductor-metal phase transition was revealed. The complex Mott-Peierls character of the phase transitions in all the listed strongly correlated compounds has been established. It is shown that as the degree of oxidation of the V atom increases, the numerical value of the metallic conductivity of the high-temperature phase naturally decreases and, simultaneously, the temperature of the phase transition from the semiconductor to the metallic state increases. Keywords: phase transitions, Magneli series, electron correlations, hybridization of atomic orbitals.

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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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Chiu, Wan-Ting, Tso-Fu Mark Chang, Masato Sone, Hideki Hosoda, Agnès Tixier-Mita, and Hiroshi Toshiyoshi. "Developments of the Electroactive Materials for Non-Enzymatic Glucose Sensing and Their Mechanisms." Electrochem 2, no. 2 (June 21, 2021): 347–89. http://dx.doi.org/10.3390/electrochem2020025.

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A comprehensive review of the electroactive materials for non-enzymatic glucose sensing and sensing devices has been performed in this work. A general introduction for glucose sensing, a facile electrochemical technique for glucose detection, and explanations of fundamental mechanisms for the electro-oxidation of glucose via the electrochemical technique are conducted. The glucose sensing materials are classified into five major systems: (1) mono-metallic materials, (2) bi-metallic materials, (3) metallic-oxide compounds, (4) metallic-hydroxide materials, and (5) metal-metal derivatives. The performances of various systems within this decade have been compared and explained in terms of sensitivity, linear regime, the limit of detection (LOD), and detection potentials. Some promising materials and practicable methodologies for the further developments of glucose sensors have been proposed. Firstly, the atomic deposition of alloys is expected to enhance the selectivity, which is considered to be lacking in non-enzymatic glucose sensing. Secondly, by using the modification of the hydrophilicity of the metallic-oxides, a promoted current response from the electro-oxidation of glucose is expected. Lastly, by taking the advantage of the redistribution phenomenon of the oxide particles, the usage of the noble metals is foreseen to be reduced.

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Grigorenko, M., E. Chernigovtsev, O. Durov, V. Poluyanska, and A. Ievtushenko. "Wetting and contact interaction of semconductor oxide materials Ga2O3, In2O3, ZnO with metallic melts in vacuum." Uspihi materialoznavstva 2023, no. 7 (December 1, 2023): 94–103. http://dx.doi.org/10.15407/materials2023.07.010.

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Semiconductor oxide materials such as gallium, indium and zinc oxides play an important role in a development and production of a variety of electronic devices. Experimental studies of these materials allow to define, for example energetic or other physical parameters of the devices created and also to improve existing technologies of their production, metallization and joining of electrocontacts by way of brazing which require additional wetting studies. It should be noted that data on wetting of mentioned oxides by metals are practically absent in literature. Thus a detailed experimental study of the interfacial interaction, adhesion and wetting of Ga2O3, In2O3 and ZnO oxide materials with some pure metal melts (Ga, In, Sn, Au,Ge, Ag, Cu) in vacuum was performed by the sessile drop method using photo- and video- fixing including temporal and temperature dependencies of contact angles. It was found that pure metals don't wet powdery pressed specimens of Ga and In oxides in the temperature range studied and vary in a rather narrow range. For ZnO system the significant effect of experiment temperature and hold-up time on the values of contact angles for some metals (Ga, Ge, Sn, Cu) is observed. For example wetting angles for Ga change from above 90 degrees at low temperatures up to 49 and full spreading at 1173⎯1373 K. This effect may be attributed to the activation of chemical reactions, change of oxide stabilities at high temperatures at the interface. Last metals can be used as adhesive-active additions to base brazing alloy. Keywords: gallium, indium, zinc oxides, semiconductor, wetting, contact interaction, metal melt.

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Balkourani, Georgia, Theodoros Damartzis, Angeliki Brouzgou, and Panagiotis Tsiakaras. "Cost Effective Synthesis of Graphene Nanomaterials for Non-Enzymatic Electrochemical Sensors for Glucose: A Comprehensive Review." Sensors 22, no. 1 (January 4, 2022): 355. http://dx.doi.org/10.3390/s22010355.

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The high conductivity of graphene material (or its derivatives) and its very large surface area enhance the direct electron transfer, improving non-enzymatic electrochemical sensors sensitivity and its other characteristics. The offered large pores facilitate analyte transport enabling glucose detection even at very low concentration values. In the current review paper we classified the enzymeless graphene-based glucose electrocatalysts’ synthesis methods that have been followed into the last few years into four main categories: (i) direct growth of graphene (or oxides) on metallic substrates, (ii) in-situ growth of metallic nanoparticles into graphene (or oxides) matrix, (iii) laser-induced graphene electrodes and (iv) polymer functionalized graphene (or oxides) electrodes. The increment of the specific surface area and the high degree reduction of the electrode internal resistance were recognized as their common targets. Analyzing glucose electrooxidation mechanism over Cu- Co- and Ni-(oxide)/graphene (or derivative) electrocatalysts, we deduced that glucose electrochemical sensing properties, such as sensitivity, detection limit and linear detection limit, totally depend on the route of the mass and charge transport between metal(II)/metal(III); and so both (specific area and internal resistance) should have the optimum values.

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Streitz, F. H., and J. W. Mintmire. "Charge transfer and bonding in metallic oxides." Journal of Adhesion Science and Technology 8, no. 8 (January 1994): 853–64. http://dx.doi.org/10.1163/156856194x00483.

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Journal articles on the topic 'Metallic oxides'

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