Comparative angle-resolved photoemission study of Ag nanometer films grown on fcc Fe(111) and bcc Fe(110)

Abstract

A comparative study of the electronic structures of Ag nanometer films on pseudomorphic metastable fcc Fe(111) and bulklike bcc Fe(110) substrates has been carried out to investigate their quantized electronic structures. From low-energy electron diffraction and angle-resolved photoemission spectra, it has been confirmed that Ag nanofilms on both substrates grow in fcc [111] direction under optimized growth conditions. The photoemission spectra of both Ag nanofilms exhibit spectral features due to quantum-well (QW) states derived from the Ag $sp$ valence electron. The nanofilm-thickness dependences of the binding energy of QW states are reproduced with calculated results based on a phase accumulation model. From the angle-resolved photoemission measurements, the effective mass of QW states along the direction parallel to the nanofilm surface were directly determined. From these results, we discuss the quantized electronic structures in Ag nanofilms grown on both bcc Fe and fcc Fe substrates.