First-principles Investigation for Quantum-well States in the Agn/Fe(001) (n=1, 2, and 3) System

초록

Magnetism and electronic structures of ultrathin films, consisting of alternating noble metals and ferromagnetic metals, have attracted much attention [1-3]. These systems are exposed to exhibit so-called quantum-well (QW) states due to confined electrons in noble metal layer. Very recently, Paniago et al. [1] investigated the photoemission spectra of Ag/Fe(001) system by spin-integrated angle resolved photoemission spectroscopy (ARUPS). They examined the variation of film states depending on the number of Ag overlayers. However, there are other reports which claim strong evidencies for the sp-and d-QW states in the Ag overlayers on the Fe(100) whisker, from the photoemission experimental data [2,3]. In this study, we have calculated the electronic structures for the Agn/Fe(001) (n=1,2, and 3) system by using a prcise first-principles calculation in terms of the all-electron full-potential linearized augmented plane wave (FLAPW) method [4] within the generalized gradient approximation (GGA). We also investigated the variation of surface and interface states depending on the thickness of Ag overlayers and the magnetism of Fe substrate layers.