The growth of GaMnAs films by molecular beam epitaxy using arsenic dimers

Abstract

We demonstrate that GaMnAs films grown with As 2 have excellent structural, electrical and magnetic properties comparable or better than similar films grown with As 4. Using As 2, a Curie temperature on post-growth annealed samples of 140 K has been achieved. Also films showing metallic conduction have been obtained over a much wider range of Mn concentrations from 1.5% to 8% than has previously been reported for films grown with As 4. The improved properties of the films grown with As 2 may be related to the lower concentration of antisite defects at the low growth temperatures employed.