Co-W磁性薄膜应变对其有效磁晶各向异性能的影响

Effect of Strain of Co-W Thin Film on Effective Magnetic Anisotropy Energy

利用磁控溅射在250℃的MgO(220)单晶基片上先后沉积Cr(100 nm)下底层和不同厚度(9~80 nm)的Co-11%W(原子分数)磁性层,二者取向附生生长关系为Cr(112)[111]∥Co-W(1010)[1210]和Cr(112)[110]∥Co-W(1010)[0001].随着膜厚的增加,Co-W在薄膜面内的压应变(ε<0)由-0.388 4%减小到-0.271 1%,Co-W在薄膜法线方向拉应变(ε>0)从0.781 3%减小到0.544 5%,相应地其有效磁晶各向异性能一级常数Ke1ff由3.82×106减小到2.58×106erg/cc.该结果表明通过设计磁性层和下底层之间的应变状态,可以达到调节磁记录介质有效磁晶各向异性能的作用.

Co-llat% W films with different thicknesses （9--80 nm） were deposited on MgO （220） single crystal substrate with Cr underlayer （100 nm） by magnetron sputtering. The epitaxial growth relationship between Cr and Co-W layer is Cr（112）[117]//Co-W（1010） [ 12101 and Cr（112） [ 110 J//Co-W （1010） [ 00011. With the increasing of Co-W film thickness, the in- plane strain of Co-W layer decreases from - 0. 388 4 % to 0.271 1%, while the out-of-plane strain decreases from 0. 781 3 % to 0. 544 5 %, and the first order effective magnetic anisotropy constant K^ff decreases from 3.82 ~ 106 erg/cc to 2.58 ~ 106 erg/cc correspondingly. The results showed that the effective magnetic animtropy energy of magnetic layer can be tuned by adjusting the strain between underlayer and magnetic layer.