SmCrO3中由温度诱导的自旋重组和交换偏置效应

Perovskite SmCrO3 ceramics had been synthesized by a conventional solid state reaction. X-ray diffraction shows that this compound possesses an orthorhombic structure with Pnma space group. Magnetic behavior was investigated by measurement of temperature dependent magnetization and isothermal hysteresis loops. The results reveal that there exists strong temperature dependence of magnetic ordering at low temperatures. The antiferromagnetic transition around ~197 K is attributed to the antiferromagnetic ordering of the Cr3+ spins and the decrease of the magnetization below ～50 K is induced by the Sm3+ ordering, indicating the existence of spin reorientation. The negative Curie-Weiss temperature ~ -860 K suggests an obvious antiferromagnetic interaction. Moreover, a negative exchange bias effect was detected below 30 K, associated with the orientation of the Sm3+ moments with respect to the canted Cr3+ components.