High-temperature phase equilibria in the oxide systems SrFe1-xGaxO2.5-SrFe1-xGaxO3 (x=0, 0-1, 0.2)

摘要

X-ray powder diffraction, Raman scattering, Equilibrium oxygen content and Conductivity data are combined to construct high-temperature phase diagrams (T vs. delta) for the oxide systems SrFe1-xGaxO2.5-SrFe1-xGaxO3, where x = 0, 0.1, and 0.2. Depending on oxygen content and gallium doping, three different structural types are shown to exist at high temperatures including cubic perovskitc-, cubic brownmillerite-, and orthorhombic brownmilleritc-type structures. Substitution of gallium for iron is shown to extend the oxygen content and temperature limits where the Cubic brownmillerite-type phase is stable. (c) 2006 Elsevier Inc. All rights reserved.