铁酸钐陶瓷的微结构和磁性能

Microstructure and Magnetic Properties of SmFeO₃ Ceramics

摘要: 以三氧化二铁和氧化钐为原材料，采用固态烧结的方法制备得到SmFeO₃陶瓷，并通过XRD，SEM、AFM、MFM，MPMS-VSM等手段对其相、微结构以及磁性能进行表征。结果表明：SmFeO₃陶瓷晶粒相对均匀且致密，并且在晶粒表面可以观察到宽度为20 nm的条纹畴结构。另外，在室温下，SmFeO₃的磁滞回线呈狭窄的矩形，在饱和磁场H_s为49999.53 Oe下饱和磁化强度M_s为1.06 emu/g。施加0.1 T的外磁场时，SmFeO₃的磁化强度从室温一直增强直到自旋重组转变温度T_SR~480 K附近，在奈尔温度T_N~700 K附近迅速降至零，此时，SmFeO₃从反铁磁性转变成顺磁性。

Abstract: SmFeO₃ ceramics were prepared by solid state sintering using Fe₂O₃ and Sm₂O₃ as raw materials. And its phase, microstructure and magnetic properties were characterized by XRD, SEM, AFM, MFM and MPMS-VSM. The results show that the ceramic grains of SmFeO₃ with pure phase are relatively uniform and compact, and the rope-type nano domain structure with the ferroelectric domain width of 20 nm can be observed on grain surfaces. At room temperature, SmFeO₃ exhibits a narrow rectangular saturated magnetic hysteresis loop with saturated magnetization M_s of 1.06 emu/g under the saturated magnetic field H_s of 49999.53 Oe. Under the external magnetic field of 0.1 T, the magnetization of SmFeO₃ increases up to the spin reorientation transition temperature T_SR about 480 K, and rapidly decreases to zero at the Néel temperature T_N of 700 K, where SmFeO₃ transforms from antiferromagnetism to paramagnetism.