Manipulating magnetic anisotropies of Co/MgO(001) ultrathin films via oblique deposition  

作　　者：Syed Sheraz Ahmad 何为 汤进 张永圣 胡泊 叶军 Qeemat Gul 张向群 成昭华 

机构地区：[1]State Key Laboratory of Magnetism and Beijing National Laboratory for Condensed Matter Physics,Institute of Physics,Chinese Academy of Sciences

出　　处：《Chinese Physics B》2016年第9期551-555,共5页中国物理B（英文版）

基　　金：Project supported by the Chinese Academy of Sciences–The World Academy of Sciences(CAS–TWAS)Fellowship Program;the National Basic ResearcProgram of China(Grant Nos.2015CB921403 and 2012CB933102);the National Natural Science Foundation of China(Grant Nos.51427801,1137435and 11274361)

摘　　要：We present a systematic investigation of magnetic anisotropy induced by oblique deposition of Co thin films on MgO（001） substrates by molecular beam epitaxy at different deposition angles,i.e.,0？,30？,45？,60？,and 75？with respect to the surface normal.Low energy electron diffraction（LEED）,surface magneto–optical Kerr effect（SMOKE）,and anisotropic magnetoresistance（AMR） setups were employed to investigate the magnetic properties of cobalt films.The values of in-plane uniaxial magnetic anisotropy（UMA） constant Ku and four-fold magnetocrystalline anisotropy constant K1 were derived from magnetic torque curves on the base of AMR results.It was found that the value of Ku increases with increasing deposition angle with respect to the surface normal,while the value of K_1 remains almost constant for all the samples.Furthermore,by using MOKE results,the Ku values of the films deposited obliquely were also derived from the magnetization curves along hard axis.The results of AMR method were then compared with that of hard axis fitting method（coherent rotation） and found that both methods have almost identical values of UMA constant for each sample.We present a systematic investigation of magnetic anisotropy induced by oblique deposition of Co thin films on MgO（001） substrates by molecular beam epitaxy at different deposition angles,i.e.,0？,30？,45？,60？,and 75？with respect to the surface normal.Low energy electron diffraction（LEED）,surface magneto–optical Kerr effect（SMOKE）,and anisotropic magnetoresistance（AMR） setups were employed to investigate the magnetic properties of cobalt films.The values of in-plane uniaxial magnetic anisotropy（UMA） constant Ku and four-fold magnetocrystalline anisotropy constant K1 were derived from magnetic torque curves on the base of AMR results.It was found that the value of Ku increases with increasing deposition angle with respect to the surface normal,while the value of K_1 remains almost constant for all the samples.Furthermore,by using MOKE results,the Ku values of the films deposited obliquely were also derived from the magnetization curves along hard axis.The results of AMR method were then compared with that of hard axis fitting method（coherent rotation） and found that both methods have almost identical values of UMA constant for each sample.

关 键 词：magnetic anisotropy oblique deposition cobalt ultrathin film anisotropic magnetoresistance 

分 类 号：O484.43[理学—固体物理]