Ferromagnetic Ga1−xMnxAs produced by ion implantation and pulsed-laser melting

Abstract

We demonstrate the formation of ferromagnetic Ga1−xMnxAs films by Mn ion implantation into GaAs followed by pulsed-laser melting. Irradiation with a single excimer laser pulse results in the epitaxial regrowth of the implanted layer with Mn substitutional fraction up to 80% and effective Curie temperature up to 29 K for samples with a maximum Mn concentration of x≈0.03. A remanent magnetization persisting above 85 K has been observed for samples with x≈0.10, in which 40% of the Mn resides on substitutional lattice sites. We find that the ferromagnetism in Ga1−xMnxAs is rather robust to the presence of structural defects.