Influence of Mn Incorporation on Molecular Beam Epitaxial Growth of GaMnN Film

To clarify the origin of ferromagnetic behavior at room temperature in wurtzite GaMnN{0001} film grown by molecular beam epitaxy on an N-polar GaN(0001) based layer on sapphire(0001) substrates, we have investigated the surface structure, composition and lattice polarity of GaMnN films using coaxial impact-collision ion scattering spectroscopy. It was found that (1) incorporation of Mn atoms into GaN film suppresses the inversion of lattice polarity at the initial stage of GaMnN growth, (2) Mn atoms occupy substitutional sites of Ga atoms in the wurtzite GaN crystal, and (3) no notable surface segregation of Mn atoms occurs.