Theory of carrier mediated ferromagnetism in dilute magnetic oxides

Abstract

We analyze the origin of ferromagnetism as a result of carrier mediation in diluted magnetic oxide semiconductors in the light of the experimental evidence reported in the literature. We propose that a combination of percolation of magnetic polarons at lower temperature and Ruderman-Kittel-Kasuya-Yosida ferromagnetism at higher temperature may be the reason for the very high critical temperatures measured (up to ~700 K).Comment: 10 pages, 3 figures; formulae and references added, discussion extende