Magnetic and neutron diffraction study on perovskites La1-xSrxCrO3

摘要

Magnetic properties of perovskite-type compounds La1-xSrx CrO3 (x = 0, 0.05, 0.10, 0.15, 0.20, and 0.25) have been reported. Their DC magnetic susceptibilities were measured from 4.5 K to 320 K. All these compounds showed an antiferromagnetic transition and their Neel temperatures decreased linearly from 286 K for LaCrO3 with increasing Sr substitution. Below the Ni el temperatures, other two magnetic transitions were furthermore observed for almost all the compounds. Below the Neel temperatures, all the compounds except LaCrO3 showed magnetic hysteresis, The initial magnetization curve indicates the existence of the metamagnetic property below 20 ii, Powder neutron measurements were performed at room temperature, 250 K and 50 K for La0.85Sr0.15 CrO3. It was found that the crystal phase and magnetic transition occurred between 50 It and 250 K. The crystal structure at 250 K is rhombohedral with space group R (3) over bar c, and it transforms to an orthorhombic structure with space group Pnma at 50 K. The magnetic structures at 50 K and at 250 K are both the C-type. The direction of magnetic moments is directed to [111] of the rhombohedral unit cell at 250 K and changes to be parallel to the z-axis of the orthorhombic unit cell (Pnma) at 50 K. (C) 1998 Academic Press. [References: 11]