Separation of the different contributions to FMR linewidth of microwave ferrites up to 40 GHz

The ferromagnetic resonance linewidth ( Delta H) of LiTiZn ferrites is measured in a broad ranged of frequencies (up to 40 GHz) and temperatures (between 77 K and 400 K). This allows a determination of the anisotropy field (H_a) and of the first anisotropy constant (K₁). The porosity contribution ( Delta H_p) does not correspond to the theory at all and an approach is presented to the porosity theory which fits present Delta H_p data. Results confirm the expected decrease of anisotropy with the double Ti-Zn substitution.