NiFe/Mo多层膜界面的电子显微学研究

HREM STUDY OF THE INTERFACIAL STRUCTURE OF NiFe/Mo MAGNETIC MULTILAYERS

用高分辨电子显微学方法研究了Ｎｉ８０Ｆｅ２０／Ｍｏ磁性多层膜，结果表明：（１）多层膜的结晶状态，随Ｍｏ非磁性层厚度而变化．当Ｍｏ层厚度为０７ｎｍ时，多层膜基本为非晶；当Ｍｏ层厚度大于１６ｎｍ时，Ｍｏ层和ＮｉＦｅ层内分别结晶为体心立方和面心立方多晶，层内晶粒尺寸为２—６ｎｍ．（２）在Ｍｏ层厚度为１．６和２．１ｎｍ的多层膜中，ＮｉＦｅ层和Ｍｏ层之间存在两种取向关系：（１１０）Ｍｏ∥（１１１）ＮｉＦｅ，［１１１］Ｍｏ∥［１１０］ＮｉＦｅ和（１１０）Ｍｏ∥（１１１）ＮｉＦｅ，［００１］Ｍｏ∥［１１０］ＮｉＦｅ．（３）ＮｉＦｅ层和Ｍｏ层之间有较清晰的界面．界面附近３—４个原子层范围内，ＮｉＦｅ和Ｍｏ的面间距分别相对块状晶体沿生长方向膨胀和压缩．讨论了界面附近面间距的变化，并根据该多层膜显微结构特征，讨论了此系统未显示巨磁电阻效应的原因．

Abstract The [(Ni 80 Fe 20 ) 1.4nm /Mo x nm ] 30 magnetic multilayers( x =0.7,1.6,2.1) have been investigated by selected area electron diffraction and high resolution electron microscopy (HREM).It is revealed that:(a) The structure of the NiFe/Mo multilayer changes with the increase of the thickness of Mo spacer layer. The NiFe and Mo layers are mainly amorphous as the Mo spacer is 0.7 nm in thickness, and crystallized into polycrystalline fcc NiFe and bcc Mo layers as the Mo spacer is thicker than 1.6nm. (b) For the multilayers with Mo spacer of 1.6nm and 2.1nm in thickness , there are two types of orientation relationship between the fcc NiFe and bcc Mo:(110) Mo ∥(111) NiFe ,11] Mo ∥[11