本文采用分子束外延方法制备出MnSi薄膜和MnSi1.7纳米线,利用扫描隧道显微镜进行观察,采用X射线光电子能谱仪系统地分析了MnSi薄膜和MnSi1.7纳米线的Mn2p和Si2p.结果表明厚度为-0.9nm的MnSi薄膜表面为/3×/3重构,MnSi1.7纳米线长50ff--1500nm,宽16—18nm,高-3nm.MnSi薄膜的Mn2p1/2和Mn2p3/2峰位与MnSil.7纳米线相同,均分别为649.7eV和638.7ev结合能在640-645eV和-653.8eV处的锰氧化合物的Mn2ps/2和Mn2p1/2峰证明在短暂暴露于空气中后MnSi薄膜和MnSi1.7纳米线表面有氧化层形成.相对于纯si的si2p谱,两种锰硅化合物的Si2p谱向低结合能方向发生了位移,表明随着锰硅化合物的形成Si的化学环境发生了变化.
Manganese silicides are promising industrial materials in optoelectronics and microelectronics fields. The study of electronic structures of manganese silicide film and nanowires is essential for a deeper understanding of their properties. In this paper, MnSi film and MnSil.7 nanowires are prepared by molecular beam epitaxy method, and then observed by scanning tunneling microscopy (STM). The Mn 2p and Si 2p of MnSi film and MnSil. 7 nanowires are comprehensively studied using X-ray photoelectron spectroscopy (XPS). The results demonstrate that MnSi film with ,-0.9 nm high is /3×/3 reconstruction, and that the MnSi1.7 nanowires are about ,-3 nm high, 16--18 nm wide and 500---1500 nm long. The binding energies of the Mn 2pl/2 level and Mn 2pa/2 level for MnSi film are 649.7 and 638.7 eV, respectively, which coincide with those of MnSil.7 nanowires. The Mn 2p3/2 and Mn 2pt/2 peaks which are located at 640----645 eV and ~653.8 eV indicate that an oxide layer formed on the surfaces of film and nanowires because of short-time exposure to the atmosphere. The negative chemical shifts for MnSi film and MnSil.7 nanowires from Si2p spectra indicate that with the formation of manganese silicides, the chemical state of Si is changed.