Rietveld Refinement
Mostrando 13-24 de 68 artigos, teses e dissertações.
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13. Fish Bone as a Source of Raw Material for Synthesis of Calcium Phosphate
Fish bone is rich in calcium carbonate, which makes it an alternative source of low cost calcium carbonate for the synthesis of calcium phosphate bioceramic for use in bone regeneration. The calcium phosphate bioceramic was prepared by a wet precipitation method with acid and base reactions. The synthesized bioceramic was characterized in terms of X-ray diff
Mat. Res.. Publicado em: 28/10/2019
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14. Acid Leaching-Based Synthesis of CdS Yellow Ceramic Pigment with Discarded Ni-Cd Batteries
There is increasing interest in the ceramic industry in the development of pigments with intense tonalities that can be produced from low-cost alternative raw materials and also can fulfill technological and environmental requirements. This work reports on the preparation and characterization of CdS yellow ceramic pigment derived from Ni-Cd batteries through
Mat. Res.. Publicado em: 14/10/2019
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15. Mineralogical Evolution of Magnetic Rhodic Oxisols under Different Lithological Influences in Brazil
ABSTRACT Ferrimagnetic Fe-oxides are important soil components, which are present in most of the agricultural soils of Brazil. Distinction, origin, and assessment of the influence of these minerals on magnetism and geochemistry is a challenge for mineralogists. This study aimed to characterize mineralogically Fe-rich Rhodic Oxisols ( Latossolos Vermelhos ) o
Rev. Bras. Ciênc. Solo. Publicado em: 30/09/2019
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16. Caracterização do composto de CuCr2O4 obtido pelo método da reação de combustão em solução
RESUMO O material CuCr2O4 foi sintetizado pela reação de combustão em solução e tratado termicamente na faixa de 600 à 1100oC, afim de verificar a evolução das fases. O composto foi carcterizado estrutural e morfologicamente por meio das técnicas de Difração de Raios X (DRX), refinamentos pelo método de Rietveld, Microscopia Eletrônica de Varred
Matéria (Rio J.). Publicado em: 16/09/2019
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17. Síntese e caracterização de cobaltita de níquel (NiCo2O4) obtida pelométodo dos precursorespoliméricos
RESUMO A cobaltita de níquel (NiCo2O4) de estrutura do tipo espinélio apresenta baixa estabilidade térmica em torno dos 400 °C, que ocasiona a perda de NiO, afetando de maneira significativa as propriedades físicas e estruturais do material produzido. Neste trabalho a cobaltita de níquel foi preparada pelo método dos precursores poliméricos. O materi
Matéria (Rio J.). Publicado em: 16/09/2019
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18. Dielectric Behavior of α-Ag2WO4 and its Huge Dielectric Loss Tangent
The microwave-assisted hydrothermal method was used to obtain α-Ag2WO4. Rietveld refinement confirmed that α-Ag2WO4 is stable in the orthorhombic phase, without secondary phase. However, field-effect scanning electron microscope analysis showed that α-Ag2WO4 nanorods surfaces contain silver nanoparticles, confirmed by the X-ray photoelectron spectroscopy
Mat. Res.. Publicado em: 02/09/2019
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19. Análisis arqueométrico de pigmentos del sitio arqueológico Tambo Colorado por difracción de rayos X sincrotrón
ABSTRACT Despite the exceptional architecture and polychromy of archaeological site of Tambo Colorado, there has been no conservation work or in the architectural structures of raw earth, nor on the surfaces. These jobs require a proper understanding of the state of conservation of the site architecture and the analysis of the materials used. With this purpo
Matéria (Rio J.). Publicado em: 20/05/2019
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20. Evidence of a new ordered vacancy crystal structure in the compound Cu3In7Te12
ABSTRACT The crystal structure of the ordered vacancy compound (OVC) Cu3In7Te12 is analyzed using powder X-ray diffraction data. It is found that this OVC crystallizes with a chalcopyrite-related structure, in the tetragonal space group P4 2c (Nº 112), with unit cell parameters and volume a = 6.1720(2) Å, c = 12.3597(8) Å, and V = 470.83(4) Å3. The Rietv
Matéria (Rio J.). Publicado em: 20/05/2019
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21. The influence of nitrogen to hydrogen ratio and temperature on thickness and phase composition in plasma nitrided Ti-6Al-4V
ABSTRACT Ti-6Al-4V was plasma nitrided using several N2/H2 ratios and substrate temperatures. In order to investigate the combined influence of these parameters on phase composition and thickness of the coatings, the phases in the as received, annealed, and nitrided Ti-6Al-4V samples were identified with Rietveld refinement. In the as-received and annealed s
Matéria (Rio J.). Publicado em: 20/05/2019
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22. Tunable Magnetic and Electrical Properties of Cobalt and Zinc Ferrites CO1-XZnXFe2O4 Synthesized by Combustion Route
Co and Zn ferrites with general formula CO1-XZnXFe2O4 (x = 0; 0,2 and 0,8) were synthesized by combustion reaction method, using urea as fuel. The structure of inverse-spinel-type ferrite were characterized through XRD using Rietveld refinement method to identify, quantify phases and determine lattice parameters. The crystallites had mean size of 37,33 nm, 4
Mat. Res.. Publicado em: 12/03/2018
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23. Influence of pH in Obtaining Indium Tin Oxide Nanoparticles by Microwave Assisted Solvothermal Method
A systematic study about synthesis of In1-xSnxO2 (ITO) nanostructured crystals by microwave-assisted solvothermal method is reported. Different solutions using InCl3.4H2O and SnCl4.5H2O precursors in ethylene glycol solvent were prepared in distinct pHs (acid and basic ones). The syntheses were performed at 200 ºC using a heating rate of 50 ºC min-1 and so
Mat. Res.. Publicado em: 22/01/2018
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24. Influence of casting heterogeneities on microstructure and mechanical properties of austempered ductile iron (ADI)
ABSTRACT An investigation was carried out to examine the influence of as-cast heterogeneities on the resulting microstructure and mechanical properties of an austempered ductile cast iron (ADI). A commercial hypereutectic ductile iron alloy with 3.59% C, 2.68% Si, 0.24% Mn and 0.46% Cu (in wt. %) was produced in a coreless induction furnace. The specimens we
Matéria (Rio J.). Publicado em: 10/08/2017