Analysis of relationship between magnetic property and crystal structure of La1-xSrxCrO3 (x=0.13, 0.15)

摘要

Dependence of do magnetization, M, of La1-xSrxCrO3 (x = 0.13, 0.15) polycrystalline specimens on external magnetic field, H, was measured at various temperatures. At higher temperatures above 274 K and 265 K for the specimens with x = 0.13 and 0.15, respectively, almost linear relationships were observed, indicating paramagnetic property. At the lower temperatures, hystereses, indicating canted antiferromagnetic property, were observed in M-H curves. The temperatures where the magnetic phase transition was observed showed agreement with those where base line shift was observed in differential scanning calorimetry (DSC) measurement. In the M-H curves of La1-xSr-xCrO3 (x = 0.13, 0.15), saturation magnetization, M-s, was not observed at external magnetic fields as high as 70 kOe. At 226 K and 189 K for the specimens with x = 0.13 and 0.15, respectively, structural phase transition from orthorhombic- to rhombohedral-distorted perovskite was observed in DSC curves. At the temperature, abrupt decreases of residual magnetization, M-r, and variation of temperature dependence of coercive force, H, were detected. We regard that the abrupt decrease of Mr and the variation of temperature dependence of He at the structural phase transition temperature can be ascribed to discontinuous variation of Cr-O-Cr angles. (C) 2007 Elsevier Ltd. All rights reserved.