Angular dependence of spin-wave resonance and relaxation in half-metallic Sr₂FeMoO₆ films

We investigated the magnetic anisotropic parameters and spin-wave relaxation of thin films of the ferromagnetic half-metallic Sr2 FeMo O6 by ferromagnetic resonance technique. The resonance field and linewidth were recorded as a function of relative angle between applied magnetic field and crystallographic axes of the sample. The resonance field varies sinusoidally and considerable linewidth broadening occurs when the applied field is rotated parallel to the sample plane. The results are described using higher order components of anisotropy fields. We obtain the values of the cubic anisotropic field, 2 K4 M=0.096 11 T, the effective demagnetization field, 4π M-2 K2⊥ M=0.1216 T, and the planar anisotropic field, 2 K4⊥ M=-0.108 T. Moreover, we estimated the spin relaxation time (damping factor) from the analysis of the angular dependence of peak-to-peak linewidth, leading to an intrinsic value of α∼0.000 25 (Gilbert damping).