Evidence for carrier-induced high- ferromagnetism in Mn-doped GaN film

¹  KYOKUGEN, Osaka University - 1-3 Machikaneyama, Toyonaka, Osaka 560-8531, Japan
²  Department of Electronics and Information Science, Kyoto Institute of Technology - Kyoto 606-8585, Japan
³  School of Materials Science, Japan Advanced Institute of Science and Technology (JAIST) - 1-1 Asahidai Tatsunokuchi, Ishikawa 923-1292, Japan
⁴  Department of System Innovation, Osaka University - Toyonaka, Osaka 560-8531, Japan
⁵  Institute for Solid State Physics, University of Tokyo - Kashiwa 277-8581, Japan

Corresponding author: yoshii@mag.cqst.osaka-u.ac.jp

Received: 29 December 2006
Accepted: 27 March 2007

Abstract

A GaN film doped with 8.2% Mn was grown by the molecular-beam-epitaxy technique. Magnetization measurements show that this highly Mn-doped GaN film exhibits ferromagnetism above room temperature. It is also revealed that the high-temperature ferromagnetic state is significantly suppressed below 10 K, accompanied by an increase of the electrical resistivity with decreasing temperature. This observation clearly demonstrates a close relation between the ferromagnetism with extremely high and the carrier transport in the Mn-doped GaN film.