High ferromagnetic phase transition temperatures in GaMnAs layers annealed under arsenic capping

Thin GaMnAs layers grown by molecular beam epitaxy were subjected to low-temperature post growth annealing, with an amorphous arsenic capping layer deposited on the GaMnAs surface directly after the epitaxial growth. It is shown that the presence of arsenic capping at the GaMnAs surface significantly shortens the post-growth annealing times and facilitates a complete out-diffusion of Mn interstitials from GaMnAs volume.