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近来 ,超薄层的Ni80 Fe2 0 /Cu多层膜因其在巨磁电阻 (GMR)器件上的潜在应用而引起了极大的研究兴趣。众所周知 ,薄膜的电学和磁学性质明显地依赖于薄膜的微结构 ,如膜层的结晶性、应变分布、界面粗糙度以及原子互扩散等。由于巨磁电阻主要起源于界面自旋相关散射 ,有必要对Ni80 Fe2 0 /Cu多层膜的界面结构进行表征。但是 ,由于Ni80 Fe2 0 /Cu的原子散射因子差别非常小 ,用常规的X射线和电子衍射技术无法分析Ni80 Fe2 0 /Cu多层膜的界面结构。为克服这一困难 ,我们利用小角DAFS(衍射异常精细结构 )技术成功地分析了Ni80 Fe2 0 /Cu界面的原子密度和结晶性。所有样品都是用直流磁控溅射法在Si( 0 0 1 )衬底上制备的 ,其名义结构为 :Si( 0 0 1 ) /Fe( 80nm) / [Ni80 Fe2 0 ( 1 .8nm) /Cu(t) ]3 0 。其中 ,Fe为缓冲层 ,Cu层厚度分别为 0 .96nm和 0 .7nm。样品在优于 1 0 -3 Pa的真空中 ,1 5 0℃和 2 5 0℃的温度下分别进行了 1h的退火处理。用同步辐射X射线测量了样品特定衍射峰的强度随入射X射线能量的变化 ,即小角DAFS谱。结果分析表明 ,相对于Ni80 Fe2 0 和Cu体材料的原子密度差 (Δ0 )而言 ,多层膜中Ni80Fe2 0 和Cu的原子密度差别 (Δ)在退火之后明显减小 ,同时伴随着局域结晶性的改善。我们的结构还表?
Recently, the ultrathin layer of Ni80Fe2o / Cu multilayers has attracted a great deal of research interest because of its potential applications on giant magnetoresistance (GMR) devices. It is well known that the electrical and magnetic properties of a thin film obviously depend on the microstructure of the film, such as the crystallinity of the film, the strain distribution, the roughness of the interface and the mutual diffusion of atoms. Because giant magnetoresistance mainly originated from the interface spin-related scattering, it is necessary to characterize the interface structure of Ni80 Fe20 / Cu multilayer films. However, the interface structure of the Ni80Fe2o / Cu multilayers can not be analyzed by conventional X-ray and electron diffraction techniques due to the very small difference in the atomic scattering factors of Ni80Fe20 / Cu. To overcome this difficulty, we successfully analyzed the atom density and crystallinity of the Ni80 Fe20 / Cu interface using the small-angle DAFS (Diffractive Abnormal Fine Structure) technique. All samples were prepared by DC magnetron sputtering on Si (001) substrate with the nominal structure of Si (001) / Fe (80nm) / [Ni80Fe2O (1.8nm) / Cu (t)] 3 0. Among them, Fe is a buffer layer, and the thickness of the Cu layer is respectively 0.96 nm and 0.7 nm. The samples were annealed for 1 h under vacuum of better than 10 -3 Pa, respectively at temperatures of 150 ℃ and 250 ℃. The intensity of specific diffraction peak of the sample was measured by synchrotron radiation X-ray with the change of incident X-ray energy, namely the small-angle DAFS spectrum. The results show that the atomic density difference (Δ) between Ni80Fe20 and Cu in the multilayer films decreases significantly after annealing compared to the atomic density difference (Δ0) between the Ni80Fe20 and Cu bulk materials, Improve the crystallinity. Our structure is also table?