Mn- and Cr-doped InN: A promising diluted magnetic semiconductor material

Abstract

Cr- and Mn-doped InN films were successfully grown by plasma-assisted molecular beam epitaxy on c-plane sapphire substrates. Tow temperature GaN buffer layers grown by metalorganic vapor-phase epitaxy were used to accommodate the large lattice mismatch between InN and sapphire. A high n-type carrier concentration of 1.5 × 1020 cm-3 was measured in InN films with 3% Cr-doping. Films of this type exhibit a well-defined in-plane magnetic hysteresis loop and remanence for temperatures varying from 5 to 300 K. The Mn-doped films, however, turned out to exhibit less clear magnetic properties. Thus, ferromagnetism in Cr-doped InN can be concluded from our measurements. © 2005 Springer Science+Business Media, Inc.