Magnetic properties of cobalt-based oxypnictide SmCoAsO  

作　　者：LI YuKe TONG Jun HAN Han ZHANG Li TAO Qian CAO GuangHan XU ZhuAn 

机构地区：[1]Department of Physics,Zhejiang University,Hangzhou 310027,China [2]Department of Physics,China Jiliang University,Hangzhou 310018,China

出　　处：《Science China(Physics,Mechanics & Astronomy)》2010年第7期1194-1198,共5页中国科学:物理学、力学、天文学(英文版)

基　　金：supported by the National Natural Science Foundation of China (Grant Nos. 10931160425 and 10634030);the Natural Science Foundation of Zhejiang Province (Grant No. Y6090564)

摘　　要：The magnetic properties of cobalt-based oxypnictides SmCoAsO are investigated by measuring magnetization,magnetoresistance and specific heat.The compound undergoes a ferromagnetic(FM) transition around Tc of 80 K,and a ferromagnetic to antiferromagnetic(AFM) transition below TN1 of about 45 K,and finally an AFM order of Sm ion at TN2 of 5.6 K.The weak FM order should originate from the itinerant 3d electrons of Co ions in the CoAs layers.We propose that the magnetic structure should be A-type AFM,which means that the FM order remains within the CoAs layer and the magnetic coupling between the CoAs layers becomes AFM below TN1 of 45 K.The AFM coupling between the CoAs layers should be very weak.A magnetic field μ0H of about 2 T may cause an AFM-FM metamagnetic transition.A rich magnetic phase diagram is established and the interplay between the 3d electrons of Co ions and 4f electrons of Sm ions is discussed.The magnetic properties of cobalt-based oxypnictides SmCoAsO are investigated by measuring magnetization,magnetoresistance and specific heat.The compound undergoes a ferromagnetic(FM) transition around Tc of 80 K,and a ferromagnetic to antiferromagnetic(AFM) transition below TN1 of about 45 K,and finally an AFM order of Sm ion at TN2 of 5.6 K.The weak FM order should originate from the itinerant 3d electrons of Co ions in the CoAs layers.We propose that the magnetic structure should be A-type AFM,which means that the FM order remains within the CoAs layer and the magnetic coupling between the CoAs layers becomes AFM below TN1 of 45 K.The AFM coupling between the CoAs layers should be very weak.A magnetic field μ0H of about 2 T may cause an AFM-FM metamagnetic transition.A rich magnetic phase diagram is established and the interplay between the 3d electrons of Co ions and 4f electrons of Sm ions is discussed.

关 键 词：OXYPNICTIDES magnetic properties phase diagram metamagnetic transition 

分 类 号：O482.5[理学—固体物理]