Tetragonal
Mostrando 1-12 de 286 artigos, teses e dissertações.
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1. Analysis of dielectric and electrical transport properties of NdFeAsO ceramic
Abstract The iron-based ceramic NdFeAsO was synthesized by the solid-state reaction method. The tetragonal crystal structure was confirmed at room temperature through the X-ray diffraction technique. The dielectric characteristics i.e. dielectric constant (εr) and loss tangent (tanδ) of the sample were studied at a wide range of temperature and frequencies
Cerâmica. Publicado em: 2022
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2. First-Principles Calculations of a New Semi-Conductive Carbon Allotrope Named ABF-Carbon
Carbon is an extremely versatile element and can generate a plethora of structures with distinct properties. Proposing new possible metastable allotropic structures for carbon has been the subject of increasing interest over the past few years. In this contribution, we present a new carbon allotrope, named ABF-Carbon, based on the connection of spiropentadie
J. Braz. Chem. Soc.. Publicado em: 2021-04
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3. Influence of sintering parameters on the microstructure and mechanical properties of nanosized 3Y-TZP ceramics
Abstract The fracture toughness of 3Y-TZP ceramics obtained from a nanocrystalline powder with an optimized microstructure and highly transformable tetragonal grains was investigated. Samples of ZrO2-3 mol% Y2O3 were sintered at temperatures between 1250 and 1400 °C, with isothermal holding times of up to 16 h. Samples sintered at 1250 °C exhibited relativ
Cerâmica. Publicado em: 2021-03
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4. Thermal decomposition and reaction sintering for synthesis of mullite-zirconia composite using kaolin, γ-alumina and zirconia
Abstract The refractory materials used in the wall of the furnaces for glass melting can be prepared from mullite-zirconia composite material. The composite of mullite/zirconia was synthesized from Iraqi kaolin, γ-alumina, and zirconia using thermal decomposition with reaction sintering at 1600 °C. Several batches were prepared with various ratios of kaoli
Cerâmica. Publicado em: 2021-03
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5. Blue-Emitting MWO4:Tm3+ (M: Sr, Ba) Phosphors Prepared by Coprecipitation Method at Room Temperature
MWO4 host matrices (M: Sr, Ba) doped with different Tm3+ concentrations (0.02, 0.04, 0.06, 0.08 and 0.10 mol%) have been successfully prepared by the coprecipitation method at room temperature. The as-prepared nanophosphors were characterized by infrared spectroscopy showing intense absorption bands in the range of 700-1000 cm-1 attributed to the symmetrical
J. Braz. Chem. Soc.. Publicado em: 2020-11
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6. A New Energetic Complex: Synthesis, Structure, and Combustion Catalysis Performance
The potential of tetrazole-based ligands for forming energetic complexes applied in pyrotechnics and propellants is demonstrated with the use of 5,5’-(1,3-phenylene)bis(1H-tetrazole) (H2BTB) to generate an energetic complex with high energy. A new energetic complex of PbII-tetrazolate, [Pb2(BTB)2(H2O)8]·5H2O (1), was synthesized and structurally character
J. Braz. Chem. Soc.. Publicado em: 2020-08
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7. Comparative Analysis of Biofilm Formation on Materials Used for the Fabrication of Implant-Supported Prostheses
Resumo O objetivo deste estudo foi comparar a formação de biofilme em materiais utilizados na confecção de próteses dentárias implantossuportadas. Vinte discos (D = 15 mm, H = 3 mm) foram confeccionados com um dos seguintes materiais restauradores: zircônia tetragonal policristalina estabilizada por ítrio (Y-TZP); titânio comercialmente puro (CP-Ti)
Braz. Dent. J.. Publicado em: 2020-08
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8. Analise experimental e modelamento por elementos finitos de ensaio de flexão biaxial de cerâmica Y-TZP
Resumo O objetivo deste estudo foi caracterizar e avaliar as propriedades físicas e mecânicas de uma zircônia experimental para aplicação odontológica e comparar os resultados da resistência à flexão biaxial com a simulação de elementos finitos (MEF). Amostras de zircônia tetragonal estabilizada com ítria (Y-TZP) foram sinterizadas a 1475 °C/2
Cerâmica. Publicado em: 2020-03
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9. Multistage Phase Decomposition Behavior and Kinetics for Zr65Ni30Pd5 Ternary Amorphous Alloy
We have examined heating-induced phase decomposition and its kinetics for Zr65Ni30Pd5 amorphous alloy in an argon atmosphere. The amorphous phase decomposes through three stages in the order of amorphous → icosahedral quasicrystal (I-Q) + amorphous → approximant cubic Zr2(Ni,Pd) → tetragonal Zr2Ni + tetragonal Zr2Pd phases. The approximant crystalline
Mat. Res.. Publicado em: 20/01/2020
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10. Morphology, Crystalline Structure and Chemical Composition Of MAO Treated Ti-15Zr-Mo Surfaces Enriched with Bioactive Ions
In this study, MAO treatment was used to enrich, with bioactive Ca, Mg and P atoms, as-casted and heat-treated Ti-15Zr-xMo (x = 0, 5, 10 and 15 wt%) alloys, for potential use as advanced metallic biomaterials. The chemical composition of the surface was evaluated by EDS and XPS measurements. The morphology and microstructure was analyzed by OM and SEM images
Mat. Res.. Publicado em: 09/12/2019
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11. Study of Structural and Electric Properties of the PZT 52/48 Doped With Er+3
The scientific community has shown a growing interest in relating to the ferroelectric materials and it has made an effort to develop them. Among these several ferroelectric materials, we proposed to investigated Pb(ZrTi)O3 doped with distinct Er+3 concentrations. Our aim was to investigate how the erbium affects the PZT electrical properties. To determine t
Mat. Res.. Publicado em: 25/11/2019
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12. Fracture Load and Failure Mode of CAD-on Ceramic Structures
Resumo Este estudo avaliou a carga de fratura (Cf) e o modo de falha de estruturas cerâmicas fabricadas pela técnica CAD-on (Ivoclar Vivadent), testando as hipóteses de que a Cf das estruturas multicamadas é governada pela resistência da cerâmica de cobertura e o lascamento é mais frequente nas estruturas em multicamadas do que em monolíticas. Corpos
Braz. Dent. J.. Publicado em: 22/07/2019