Phase Transformations of Perovskite La_0.64(Ba_1−xCa_x)_0.36FeO_3−δ Investigated by Mechanical Spectroscopy

Abstract

Herein, perovskite La0.64(Ba1−x Ca x )0.36FeO3−δ () samples are synthesized and investigated by X‐ray diffraction and mechanical spectroscopy. The room‐temperature structure of La0.64Ba0.36FeO3−δ is a mixture of orthorhombic and cubic phases. The structures of calcium‐doped La0.64(Ba1−x Ca x )0.36FeO3−δ are orthorhombic at room temperature. A modulus dip is observed above room temperature in La0.64(Ba1−x Ca x )0.36FeO3−δ () samples. This corresponds to a phase transition from orthorhombic to rhombohedral structure with increasing temperature. The effect of oxygen nonstoichiometry on the room‐temperature structure and phase transition is observed by mechanical spectroscopy.