Abstract
Cu-doped GaN thin films are grown by plasma-assisted molecular beam epitaxy. With nitrogen plasma only, films phase segregate into GaN and Cu-rich alloys. In contrast, when nitrogen-hydrogen plasma is used, the films are single-phased GaCuN, with as high as 0.04. Contrary to earlier studies, however, these films are not ferromagnetic, but rather paramagnetic in nature. First-principles calculations indicate that although each substitutional Cu exhibits a moment of 1 /Cu, it can be suppressed by neighboring intrinsic defects such as N split interstitials.
- Received 10 October 2011
DOI:https://doi.org/10.1103/PhysRevB.85.075207
©2012 American Physical Society