Size-dependent exchange bias in single phase Mn_3O_4 nanoparticles  

作　　者：王松伟 张鑫 姚蓉 饶光辉 

机构地区：[1]School of Materials Science and Engineering, Guilin University of Electronic Technology [2]Guangxi Key Laboratory of Information Materials, Guilin University of Electronic Technology

出　　处：《Chinese Physics B》2016年第11期502-506,共5页中国物理B（英文版）

基　　金：Project supported by the National Natural Science Foundation of China(Grant No.11464007);the Natural Science Foundation of Guangxi,China(Grant Nos.2012GXNSFGA060002 and 2014GXNSFBA118241);the Guangxi Key Laboratory of Information Material Foundation,China(Grant No.131021-Z);the Guangxi Department of Education Foundation,China(Grant Nos.YB2014120 and KY2015YB104)

摘　　要：Glassy magnetic behavior and exchange bias phenomena are observed in single phase Mn3O4 nanoparticles.Dynamics scaling analysis of the ac susceptibility and the Henkel plot indicate that the observed glassy behavior at low temperature can be understood by taking into account the intrinsic behavior of the individual particles consisting of a ferrimagnetic（FIM） core and a spin-glass surface layer.Field-cooled magnetization hysteresis loops display both horizontal and vertical shifts.Dependence of the exchange bias field（HE） on the cooling field shows an almost undamped feature up to 70 kOe,indicating the stable exchange bias state in Mn3O4.HE increases as the particle size decreases due to the higher surface/volume ratio.The occurrence of the exchange bias can be attributed to the pinning effect of the frozen spin-glass surface layer upon the FIM core.Glassy magnetic behavior and exchange bias phenomena are observed in single phase Mn3O4 nanoparticles.Dynamics scaling analysis of the ac susceptibility and the Henkel plot indicate that the observed glassy behavior at low temperature can be understood by taking into account the intrinsic behavior of the individual particles consisting of a ferrimagnetic（FIM） core and a spin-glass surface layer.Field-cooled magnetization hysteresis loops display both horizontal and vertical shifts.Dependence of the exchange bias field（HE） on the cooling field shows an almost undamped feature up to 70 kOe,indicating the stable exchange bias state in Mn3O4.HE increases as the particle size decreases due to the higher surface/volume ratio.The occurrence of the exchange bias can be attributed to the pinning effect of the frozen spin-glass surface layer upon the FIM core.

关 键 词：magnetization attributed hysteresis susceptibility cooled scaling understood frozen intrinsic sharply 

分 类 号：TQ137.12[化学工程—无机化工] TB383.1[一般工业技术—材料科学与工程]