Co/Cu(111)薄膜生长和退火过程中的扩散

利用同步辐射角分辨光电子能谱和俄歇电子能谱研究了CoCu(111)分子束外延薄膜在生长和退火过程中的电子结构.实验发现:随着Co膜厚度的增加,Cu的sdz2杂化带能级位移相应增大,证实了界面间发生了互混;退火过程中存在表面扩散,而非通过界面的体扩散.并把这两种不同过程的扩散的内在动力归结为Co的表面自由能显著大于Cu的表面自由能 关键词： 表面扩散和界面混合物形成 固体表面能 表面态和能带结构

Diffusion during growth and annealing of Co/Cu(111) films

Electronic structure of MBE grown Co/Cu(111) films was studied by synchrotron radiation angular resolved photoemission spectra and auger electron spectra during the process of growth and annealing.The experiment reveals that:the energy shift of s\|d z 2 hybridized band of copper increases with thickening of the coverage of cobalt,which proves that atomic intermixing occurrs at the interface, and there is mainly surface diffusion,not bulk interdiffusion during annealing.We attribute the diffusion in the two different processes to one driving force,i.e.the surface free energy of cobalt is remarkably larger than that of copper.