文摘
Previously, high-temperature ferromagnetism with a Curie temperature in excess of 400 K was reported in the magnetic semiconductor (In,Mn)Sb films grown by metal鈥搊rganic vapor phase epitaxy (MOVPE). To determine the role of Mn distribution on its magnetic properties, the Mn 2p core-level X-ray photoelectron spectroscopy (XPS) of (In,Mn)Sb films was measured. For films grown on an InSb substrate, Mn composition is spatially inhomogeneous and its concentration increases with increasing deposition temperature. Spin鈥搊rbit splitting energy of the Mn 2p core-level was found to increase with increasing Mn concentration. From the dependence of the measured spin鈥搊rbit splitting energy on the Mn concentration, evidence of atomic-scale Mn cluster formation was observed. The measured magnetic moment per Mn atom decreases from 3.0 渭B/Mn to 1.8 渭B/Mn with increasing Mn concentration, which is attributed to atomic-scale clusters that are ferromagnetic or ferrimagnetic. This detailed investigation gives an insight into the Mn distribution, phase composition and origin of magnetism in MOVPE-grown (In,Mn)Sb magnetic thin films.