Ferromagnetic resonance inGa1−xMnxAs:Effects of magnetic anisotropy

Abstract

This paper describes a systematic study of ferromagnetic resonance (FMR) carried out on a series of specimens of the ferromagnetic semiconductor ${\mathrm{Ga}}_{1-x}{\mathrm{Mn}}_x\mathrm{As}$ in thin film form. The GaMnAs layers were grown by low-temperature molecular beam epitaxy either on GaAs or on GaInAs buffers, the two buffers being used to obtain different strain conditions within the ferromagnetic layer. Our aim has been to map out the dependence of the FMR position on temperature and on the angle between the applied magnetic field and crystallographic axes of the sample. The analysis of the FMR data allowed us to obtain the values of the cubic and the uniaxial magnetic anisotropy fields—i.e., those which are associated with the natural (undistorted) zinc blende structure and those arising from of strain.