Spin-lattice coupling and exchange bias in perovskite La0.64Sr0.36FeO3−δ

Phase Transformations of Perovskite La0.64(Ba1−xCax)0.36FeO3−δ Investigated by Mechanical Spectroscopy

“…In perovskite, elastic properties at the tilting transition can be explained by Landau theory by considering the quadratic coupling between strain and the tilting-order parameter. [25,30] This is similar the case in BaTiO 3 [31] where the elastic properties in ferroelectric phase transitions can be explained by Landau theory by considering the quadratic coupling between strain and the spontaneous polarization. A modulus dip accompanied with an internal friction peak was observed at the ferroelectric phase transitions from rhombohedral to orthorhombic phase, from orthorhombic to tetragonal phase in BaTiO 3 .…”

“…[36,37] In perovskite ferrites, usually three kinds of transitions were observed. They are the metal-insulator transitions, [7][8][9][10]26] paramagnetic-antiferromagnetic transitions, [25] and octahedra tilting transitions. [21,[23][24][25] The metal-insulator transitions occur below room temperature.…”

“…They are the metal-insulator transitions, [7][8][9][10]26] paramagnetic-antiferromagnetic transitions, [25] and octahedra tilting transitions. [21,[23][24][25] The metal-insulator transitions occur below room temperature. [7][8][9][10]26] In our previous study, no elastic anomaly was observed at the paramagnetic-antiferromagnetic transition in La 0.64 Sr 0.36 FeO 3Àδ .…”

“…Mechanical spectroscopy is a well-known probe for the study of phase transitions and mechanical relaxations in solids. [22][23][24][25][26][27][28][29][30][31][32][33][34] It has been successfully applied in the study of the tilting transitions. [23][24][25][28][29][30] A clear step-like decrease of modulus below the tilting transition from cubic to rhombohedral was observed in La 1/3 Sr 2/3 FeO 3Àδ [23] and LaAlO 3 by mechanical spectroscopy, [29] which was resulted from the quadratic coupling between strain and the tilting-order parameter.…”

“…[22][23][24][25][26][27][28][29][30][31][32][33][34] It has been successfully applied in the study of the tilting transitions. [23][24][25][28][29][30] A clear step-like decrease of modulus below the tilting transition from cubic to rhombohedral was observed in La 1/3 Sr 2/3 FeO 3Àδ [23] and LaAlO 3 by mechanical spectroscopy, [29] which was resulted from the quadratic coupling between strain and the tilting-order parameter. [25,30] A modulus dip accompanied with an internal friction peak was observed in La 0.75 Sr 0.25 FeO 3Àδ , which corresponds to the tilting transition from rhombohedral to orthorhombic perovskite with decreasing temperature.…”