Thermodynamic stability of calcium vanadium garnet ferrites upon formation of substitutional solid solutions

Abstract

The thermodynamic stability of calcium vanadium garnet ferrites Ca 3Fe3.5 - x Ti2x V1.5 - x O 12 upon isomorphic substitution of titanium ions for iron and vanadium ions was studied by the EMF method using ZrO2(Y 2O3) ceramic solid electrolyte. Temperature-dependent ?G 0 was determined. Isomorphic substitutions of titanium ions for iron and vanadium ions in the inequivalent sublattices of the garnet structure in a temperature range of 1100-1483 K cause changes in ?G 0 due to the entropy and enthalpy components and has a minimal value when x = 0.15. © 2013 Pleiades Publishing, Ltd.