Ga On Wurtzite GaN : Initial Stages Of Growth By Molecular Beam Epitaxy

Submitted for the MAR08 Meeting of The American Physical Society Ferromagnetic Mn3−δGa On Wurtzite GaN: Initial Stages Of Growth By Molecular Beam Epitaxy KANGKANG WANG, ABHJIT CHINCHORE, ERDONG LU, WENZHI LIN, JEONGIHM PAK, ARTHUR R. SMITH, Nanoscale and Quantum Phenomena Institute, Department of Physics and Astronomy, Ohio University, Athens, OH 45701 — Ferromagnetic (FM) metal/wide bandgap bilayers are of great interest due to their potential for novel spintronics applications, such as blue and ultra-violet spin light-emitting diodes[1]. It has been reported[2] that Mn3−δGa, a promising FM alloy, can be grown epitaxially on top of w-GaN(0001) with controllable magnetism via controlling of the Mn:Ga flux ratio. Here we report studies on the initial stages of growth of MnGa on w-GaN. Growth experiments were carried out in a UHV chamber using molecular beam epitaxy with rf (N2)-plasma, on both Nand Ga-polar substrates. Reflection high-energy electron diffraction (RHEED) data suggest that at the initial stages of growth, the surface structures depend on the substrate polarity. This may be due to the structural differences between the N-polar and the Ga-polar GaN surfaces. Stoichometry dependence of initial stages of growth is also being investigated. This work has been supported by DOE (Grant No.DE-FG02-06ER46317) and NSF (Grant No.0304314). Equipment support from ONR is also acknowledged. [1] S.A.Wolf et al, Science 294, 1488 (2001) [2] E.Lu et al, Phys.Rev.Lett. 97, 146101 (2006) Kangkang Wang Nanoscale and Quantum Phenomena Institute, Dept. of Physics and Astronomy, Ohio University, Athens, OH 45701 Date submitted: 26 Nov 2007 Electronic form version 1.4