Ferromagnetic resonance investigation of magnetic anisotropy in Ga1-xMnxAs synthesized by ion implantation and pulsed laser melting

A systematic investigation of ferromagnetic resonance (FMR) was carried out on Ga1-xMnxAs layers synthesized by Mn ion implantation into GaAs followed by pulsed laser melting. Angular and temperature dependences of FMR were measured on layers prepared on GaAs (001), (110), and (311) surfaces. The observed angular dependence of FMR can be understood in terms of contributions from cubic anisotropy fields defined by the crystal symmetry of Ga1-xMnxAs and uniaxial anisotropy fields perpendicular or parallel to the film plane. For completeness, the angular dependence of the FMR linewidth was also investigated and was found to be dominated by broadening ascribed to local inhomogeneities in magnetic anisotropy. Our results show that both the magnetic anisotropy and the FMR linewidth in (Ga,Mn)As prepared by ion implantation are similar to those observed on Ga1-xMnxAs samples grown by low-temperature molecular beam epitaxy, indicating that the two very different growth methods lead to materials with fundamentally similar magnetic properties.