Phase relations in the SrO – GdO1.5 – FeO1.5 system

Abstract

The lack of data systematization on the coexistence and stability of compounds formed in the SrO – GdO1.5 – FeO1.5 system at temperatures above 1100°C determines the interest in a more detailed study of this system. The research was focused on studying the stability of phases formed in the pseudobinary section (1-х)GdFeO3 – хSrO in the temperature range 1200- 1400°C in air. The interaction of components in the SrO – GdO1.5 – FeO1.5 system was studied by the method of annealing and quenching followed by physicochemical analysis. The phase composition and sequence of phase transformations were characterized by powder X-ray diffraction. Phase relations results in the SrO – GdO1.5 – FeO1.5 system in air were systematized. The formation of three complex perovskite-like oxides GdSr2FeO5, GdSrFeO4, Gd2SrFe2O7, located on the GdFeO3 – SrO binary section was established. Information on interplanar distances and reflection intensities of the GdSr2FeO5 compound has been supplemented and the existence of a miscibility gap for Gd1-xSrxFeO3-α solid solutions existing in the range 0.05≤x≤0.51 at 1400°C has been shown. Data on thermal stability of complex gadolinium ferrites based on GdO1.5 – SrO – FeO1.5 system has been expanded.