Optimization of the growth of Ga1− xMnxN epilayers using plasma‐assisted MBE

A systematic compositional and structural study of GaN:Mn epilayers grown by molecular beam epitaxy (MBE) was performed, with a special attention to the dependence on the growth conditions. The growth diagram related to the Ga/N flux ratio for GaN was modified by adding Mn flux. In particular, the stable Ga-bilayer coverage on the surface for the Ga-rich condition was reduced in the presence of Mn. The Mn incorporation in the epilayers was found to be strongly dependent on the Ga/N flux ratio. The X-ray diffraction (XRD) and extended X-ray absorption fine structure (EXAFS) measurements revealed a clear contrast between the precipitation of a perovskite compound GaMn 3 N at Mn compositions higher than 1.7%, and the single phase of the wurtzite Ga 1-x Mn x N at lower Mn compositions. The single-phase epilayers (x < 1.7%) exhibited intrinsic ferromagnetic behaviors at room temperature.