Abnormal Temperature Dependence of Coercivity in Cobalt Nanowires  

作　　者：FAN Xiu-Xiu HU Hai-Ning ZHOU Shi-Ming YANG Mao DU Jun SHI Zhong 范秀秀;胡海宁;周仕明;杨茂;杜军;时钟(Surface Physics State Laboratory and Department of Physics,Fudan University,Shanghai 200433;School of Mathematics and Physics,Shanghai University of Electric Power,Shanghai 200090;Department of Physics,Tongji University,Shanghai 200092;Department of Physics,Nanjing University,Nanjing 210093)

机构地区：[1]Surface Physics State Laboratory and Department of Physics,Fudan University,Shanghai 200433 [2]School of Mathematics and Physics,Shanghai University of Electric Power,Shanghai 200090 [3]Department of Physics,Tongji University,Shanghai 200092 [4]Department of Physics,Nanjing University,Nanjing 210093

出　　处：《Chinese Physics Letters》2012年第7期257-260,共4页中国物理快报（英文版）

基　　金：Supported by the National Natural Science Foundation of China under Grant Nos 11074112 and 10974032;the National Basic Research Program of China under Grant Nos 2009CB929201 and 2010CB923401;the Key Project of the Ministry of Education of China under Grant No 210074;the Innovation Program of Shanghai Municipal Education Commission(No 10ZZ117).

摘　　要：Co nanowire arrays have been fabricated into anodic aluminum oxide templates at 20C by dc electrodeposition.It is shown that Co nanowires fabricated at lower and higher growth voltages have a hexagonal close packing (hcp) structure with preferred [100] orientation along the nanowire axis and a face-centered cubic (fcc) structure with preferred [220] orientation,respectively.With increasing growth voltage,the room-temperature coercivity along the nanowire axis is enhanced gradually.For fcc Co nanowires,the coercivity increases monotonically with increasing temperature while for hcp Co nanowires,a minimal coercivity is obtained along both parallel-to-axis and perpendicular-to-axis orientations with the temperature rising from 50K to 390K.The abnormal temperature dependence of the coercivity can be attributed to the competition between the shape anisotropy and magnetocrystalline anisotropy as a function of temperature.

关 键 词：NANOWIRES ANISOTROPY TEMPLATE 

分 类 号：TB3[一般工业技术—材料科学与工程]