Structural Phase Transition and Magnetic-Field Effect on the Modulated Structure in GdBaCo2O5+delta (delta %26lt; 0.5)

作者：Asaka T^*; Abe N; Kudo T; Fukuda K; Kimoto K; Matsui Y; Ishizawa N; Arima T

来源：Physical Review Letters, 2013, 110(12): 125502.

DOI：10.1103/PhysRevLett.110.125502

We investigated the crystal structures of an ordered perovskite-type cobaltate, GdBaCo2O5+delta (delta %26lt; 0.5), at elevated temperatures by transmission electron microscopy. Above the magnetic ordering temperature, we observed a first-order structural phase transition between the low-temperature tetragonal 3a(p) x 3a(p) and high-temperature orthorhombic 1a(p) x 2a(p) superstructure phases (where a(p) is the perovskite-unit cell). Upon the application of a magnetic field, an incommensurate phase emerges around the structural phase-transition temperature, which indicates a magnetic-field-induced structural phase transition via no magnetic ordering in the ordered perovskite-type cobaltate. DOI: 10.1103/PhysRevLett.110.125502

• 出版日期2013-3-19