Magnetic properties of MnAs thin films grown on GaAs (0 0 1) by MOVPE

The thickness dependence of the in-plane uniaxial anisotropy and coercive field of epitaxial MnAs thin films on GaAs (0 0 1) substrates has been determined from the magneto-optic Kerr effect. The metalorganic vapor phase epitaxy grown films are single α phase at room temperature with a B-type variant orientation. The coercive field of these films increases to a maximum for a film 35 nm thick and then decreases in thicker films. An increase in magnetic anisotropy field with increasing thickness is observed and is attributed to an increasing volume contribution to the anisotropy constant.