Behavior of precipitates in GaMnN

The behavior of precipitates in magnetic GaMnN films upon annealing was investigated. The major precipitate was Mn3GaN phase in GaMnN layers grown via molecular beam epitaxy using a single GaN precursor under high Mn flux. With heat treatment of the films, the Mn3GaN phase decomposed and a part of it was converted to magnetic Mn3Ga phase through detachment of nitrogen. The decomposition kinetics was further accelerated by neutron irradiation, which generated defects in the lattice and assisted the decomposition of the precipitates. The saturation magnetization of the homogeneous GaMnN layer was increased after the heat treatment while it was decreased in the precipitated GaMnN layer. The increase and decrease of the magnetization of the heat-treated GaMnN films was explained consistently by the role of the precipitates in the films. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)