Control of Ferromagnetism via Electron Doping in ${\mathrm{In}}_{2}{\mathrm{O}}_{3}\ensuremath{\mathbin:}\mathrm{Cr}$

Control of Ferromagnetism via Electron Doping in ${In}_{2} O_{3} ∶ Cr$

Hannes Raebiger, Stephan Lany, and Alex Zunger

Phys. Rev. Lett. 101, 027203 – Published 7 July 2008

Abstract

Carrier-induced ferromagnetism in wide-gap transparent conductive oxides has been widely discussed and debated, leading to confusion and skepticism regarding whether dilute magnetic oxides exist at all. We show from density-functional calculations within a band-gap corrected approach that ferromagnetic Cr–Cr coupling can be switched on and off via electron doping in the wide-gap transparent $n$ -type conductive oxide ${In}_{2} O_{3}$ . We show that (i) Cr does not produce in ${In}_{2} O_{3}$ any free electrons and renders the system an insulating paramagnet. (ii) Extrinsic $n$ -type doping of ${In}_{2} O_{3} ∶ Cr$ via Sn produces free electrons, whose concentration is controllable via the oxygen partial pressure. Such additional carriers stabilize a strong long-range Cr–Cr ferromagnetic coupling.