Transmission electron microscopy study on ferromagnetic (Ga,Mn)N epitaxial films

We report on the crystal structure of epitaxial (Ga,Mn)N films with Mn=0.2% grown by plasma-enhanced molecular beam epitaxy, exhibiting n-type conductivity and room temperature ferromagnetism (M-s=0.76 emu/cm(3), H-c=90 Oe). The additional diffraction spots are found in the zone axis of B=[1 (1) over bar 00] for the (Ga,Mn)N epilayer due to a single twin orientation in the closed packed hexagonal matrix. High-order Laue zone measurements reveal the expansion of lattice parameter a (3.1851-3.1865 Angstrom) by doping Mn, demonstrating that Mn ions substitute for Ga ions in the (Ga,Mn)N. (C) 2003 American Institute of Physics.