Инд. авторы:	Turkin A.I., Drebushchak V.A.
Заглавие:	Solid solutions in the MgO-Al2O3-Cr2O 3 system : EEffects of polymorphism, temperature and pressure
Библ. ссылка:	Turkin A.I., Drebushchak V.A. Solid solutions in the MgO-Al2O3-Cr2O 3 system : EEffects of polymorphism, temperature and pressure // Journal of Thermal Analysis and Calorimetry. - 2009. - Vol.95. - Iss. 1. - P.81-86. - ISSN 1388-6150. - EISSN 1572-8943.
Внешние системы:	DOI: 10.1007/s10973-008-9083-2; SCOPUS: 2-s2.0-62949200382;
Реферат:	eng: Coexisting solid solutions with spinel and corundum structure were synthesized at 1773 K and two pressures, 1 bar and 25 kbar. Samples were analyzed by electron microprobe analysis and X-ray powder diffraction. Pressure and temperature were shown to affect the properties of the solid solutions in different ways. Pressure governs the composition of the defect spinel Mg 1-xAl2O4, and temperature changes the cation distribution between coexisting phases. This allows one to separate the effects of cation exchange and magnetic contribution to the heat capacity in thermodynamic modeling. The defect spinel itself can form only because γ-Al2O3 exists, polymorph with spinel structure. Thermodynamic considerations argue in favor of eskolaite-spinel assemblages prevailing over corundum-picrochromite ones at very high temperatures deep in the Earth. © 2009 Springer Science+Business Media, LLC.
Ключевые слова:	Phase diagram; Solid solutions; Spinel; Thermodynamics; Aluminum; Chromium; Corundum; Crystallization; Electron probe microanalysis; Hematite; Phase diagrams; Polymorphism; Positive ions; Solidification; Thermodynamics; X ray diffraction analysis; Cation distributions; Cation exchanges; Coexisting phasis; Corundum structures; Solid solutions; X-ray powder diffractions; Thermodynamic modeling; Temperature changes; Spinel structures; Spinel; Pressure and temperatures; Magnetic contributions; High temperatures; Heat capacities; Corundum; Electron microprobe analysis;
Издано:	2009
Физ. характеристика:	с.81-86