ABSTRACT

We investigate the structural properties of Fe${}_{1-x}$Ni${}_x$/Cu/Fe${}_{1-x}$Ni${}_x$ ( x=0.5, non-Invar and x=0.36, Invar) trilayers deposited on Si(100) at room temperature using the dc magnetron sputtering technique in ultra high vacuum conditions taking high-purity Fe, Ni and Cu metals with Cu layer thickness 4, 6 and 8 nm for each alloy composition. The structure of the alloy films of the trilayers was investigated using x-ray diffraction and the thickness and roughness of the layers were obtained by x-ray reflectivity measurement. Both the as-prepared and annealed trilayers exhibit layered structure. The as-deposited Fe–Ni alloy in non-Invar trilayer exhibits only the fcc structure. whereas in the Invar alloy it exhibits a mixed fcc and bcc phases. Interestingly after annealing at 425${}^{\circ }$C in ultra high vacuum, the Invar alloy completely transformed to the fcc structure for all Cu thicknesses. In both Invar and non-Invar trilayers, the Bragg reflections corresponding to Fe–Ni alloy layers become sharp after annealing. The induced structural transformation in the Invar trilayer is explained using enhanced diffusion of Fe and Ni atoms at high temperatures.

摘要

我们研究了 Fe 的结构特性${}_{1-X}$你${}_X$/铜/铁${}_{1-X}$你${}_X$( x = 0.5, 非因瓦合金和x = 0.36, 因瓦合金) 在室温下使用直流磁控溅射技术在超高真空条件下沉积在 Si(100) 上的三层膜采用具有 Cu 层厚度的高纯度 Fe、Ni 和 Cu 金属每种合金成分为 4、6 和 8 nm。使用X射线衍射研究三层合金膜的结构，通过X射线反射率测量获得层的厚度和粗糙度。制备的和退火的三层都表现出分层结构。在非因瓦合金三层中沉积的 Fe-Ni 合金仅表现出 fcc 结构。而在因瓦合金中，它表现出混合的 fcc 和 bcc 相。有趣的是在 425 退火后${}^{\circ }$C 在超高真空中，Invar 合金完全转变为所有 Cu 厚度的 fcc 结构。在 Invar 和非 Invar 三层中，对应于 Fe-Ni 合金层的布拉格反射在退火后变得尖锐。使用 Fe 和 Ni 原子在高温下的增强扩散来解释因瓦合金三层中的诱导结构转变。