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Showing 1 to 13 of 13 for “"Rietveld analysis."”.
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Diffraction investigations of cement clinker and tricalcium silicate using Rietveld analysis
… There has been an increase in the use of Rietveld refinement of powder diffraction data for the analysis of cement in recent years. The method has emerged as a valuable tool for the quantitative determination of the composition of cement. A further advantage of the method is its ability to …
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Synthesis, cation distribution, and disorder of fast-ion conducting pyrochlore oxides : a combined neutron and X-ray Rietveld analysis
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 1999.
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Structure of cathode-electrolyte interfaces and correlation with ionic conductivity in Solid Oxide Fuel Cell devices
A multiple analysis approach has been used in order to investigate the chemical compatibility between different promising cathode and electrolyte materials for It-SOFC (Intermediate Temperature-Solid Oxide Fuel Cell) application, in order to evaluate how the chemical reactivity can affect the fuel …
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Magnetic and Dielectric Properties of Cu3-xNixWO6 and Cu3W1-xMoxO6
… any doping. Using Powder x-ray diffraction and Rietveld analysis, we did not observe any distortion of the cubic crystal. Ni substitution for Cu, and Mo substitution for W, will act as a negative pressure on the lattice parameter of Cu3WO6. Magnetization measurements of Cu3-xNixWO6 indicate that …
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Resorption rate tunable bioceramic: Si,Zn-modified tricalcium phosphate
… and unit volume of TCP as calculated by Rietveld analysis indicate that Si and Zn substitute for P and Ca respectively. Analysis of neutron powder diffraction data confirmed that 10% Si and Zn doped TCP has a rhombohedral structure (space group R3c, Z = 21), with the unit cell parameters …
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Studies into the ion exchange and intercalation properties of AlH2P3O10•2H2O
… including powder neutron and X-ray diffraction, Rietveld analysis, thermogravimetic analysis and environmental scanning microscopy. Monovalent ion exchange (with Na, K, Rb, Cs and Ag) gave complete and facile exchange of the host’s hydrogen ions and gave crystalline products. A thermodynamically …
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Phase equilibria, thermal expansion and symmetry relations within the HfO2-Ta2O5-TiO2-temperature system
… atomic motifs with associated material symmetry analysis and (iv) calorimetry. The tools and methodologies developed herein are essential for the development of next generation high temperature materials. The extreme temperatures were achieved by utilizing a quadrupole lamp furnace (QLF) (200 – …
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Cell parameter systematics of the binary silicate olivines: methods for the determination of composition and intracrystalline cation ordering
Multiple linear regression analysis has been used to determine the relationship between the unit cell parameters and the average radii, rM1 and rM2, of the octahedral cations in Fe-Mn, Ni-Fe, Mg-Mn, and Mg-, Fe-, and Mn-Ca binary olivines, using data from the literature. The resulting regression …
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Structural characterisation of apatite-like materials
… was complete at 100 mol% Sr substitution. Rietveld analysis confirmed that substitution of Sr for Ca in the apatite lattice resulted in an increase in the lattice parameters a and c. Interestingly small Sr-HA crystallite size was measured when Sr substitution reached 50 mol%, whereas the …
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Synthese, Charakterisierung und magnetische Eigenschaften von Nitriden des Typs MMFe3N
… even more promising properties than Fe4N. The Rietveld analysis based on XRD data shows that position 1a is the only position for rhodium, thus it is not occupying position 3c (space group Pm-3m). This finding was already predicted by the results of DFT calculation and was furthermore confirmed …
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New Experimental Data for a Re-Calibration of the Fe-Ti Oxide Thermo-Oxybarometers
… lattice parameters have been determined by Rietveld analysis. (2) At constant Ti/(Ti+Fe), cation vacancies are associated with higher Fe3+/Fetot. The latter have been determined by electron energy-loss spectroscopy on selected samples. (3) Annealing of a non-stoichiometric high-T Tmt at …
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Syntéza a stanovení vlastností čistých fází portlandského slínku a jejich polymorfů
… v současné době uskutečňována prostřednictvím Rietveldovy analýzy, která je schopna dekódovat různé difrakční linie na difrakčním záznamu za předpokladu, že je dobře znám strukturální model pro každou fázi slínku. Předmětem zkoumání této disertační práce je laboratorní příprava čistých fází …