Electrical and magnetic properties of Ga1-xGdxN grown by metal organic chemical vapor deposition

This paper presents the first report on Gd doping (0%-4%) of GaN thin films by metal organic chemical vapor deposition. The Ga1-xGdxN films grown in this study were found to be of good crystalline quality, single-phase, and unstrained, with a high saturation magnetization strength of 20 emu/cm(3) being obtained for GaN films doped with 2% Gd at room temperature. Furthermore, these films were found to be conductive with an enhanced n-type behavior suggesting that unintentional donors are responsible for stabilizing the ferromagnetic phase in as-grown Ga1-xGdxN. Additionally, it was found that this magnetization can be enhanced by n-(Si: 10(18) cm(-3)) and p-(Mg: 10(19) cm(-3)) doping to 110 emu/cm(3) and similar to 500 emu/cm(3), respectively. This paper shows empirically that holes are more efficient in stabilizing the ferromagnetic phase as compared to electrons. Overall, this research has resulted in a room temperature ferromagnetic dilute magnetic semiconductor that is conductive and whose magnetic properties can be tuned by carrier doping thus providing a path towards realizing spintronic devices. (C) 2011 American Institute of Physics. [doi:10.1063/1.3656019]