Investigation on structure and stability of cerium doped (Ba0.5Sr0.5)(Fe1-xCex)O3-δ (x = 0–1.0) oxides by Rietveld refinement

Abstract

Perovskite-type materials have been attracted due to their relevant applications in memory devices, tunable microwave displays, oxygen-permeable membranes, sensors, and capacitors. An attempt has been made here to analyze the structure of (Ba0.5Sr0.5)(Fe1-xCex)O3-ẟ (x = 0–1.0) oxides by Rietveld refinement under different space groups. It possesses cubic (space group Pm3m, Z = 1), cubic with orthorhombic, and orthorhombic (space group Pnma, Z = 4) structures for the composition x = 0, 0.10–0.60, and 0.80–1.0, respectively. The amount of cubic phase decreases from 100% to 24% with cerium content (x) = 0–0.60 and complete transformation to the orthorhombic phase occurred at x = 0.80. Moreover, single – dual - single structural phase transitions have been observed. The average bond length decreases with cerium content. The bond angles along O–B–O and B–O–B are deviated significantly due to the tilting and rotation of (Ce,Fe)O6 octahedra. The presence of distortion/oxygen vacancies makes the compound useful in industrial applications.