Effective linewidth measurements at 36 GHz in hexagonal and cubic ferrites

Abstract

Effective linewidth measurements at 36 GHz are reported for barium ferrite, several W-type single-crystal hexagonal ferrites, and for polycrystalline LiZn ferrite. In general, the effective linewidths for the W-type ferrites were relatively large - several hundred oersteds. Values of ΔHeff for the barium ferrite samples were tens of oersteds, similar to the ferromagnetic resonance (FMR) linewidths for these materials. The LiZn samples showed effective linewidths significantly below the FMR values. The results indicate that the two-magnon loss mechanism is the predominant factor in the polycrystalline LiZn, but contributes little to the ferromagnetic loss in single-crystal barium ferrite. The data for the W-type ferrites show that the intrinsic loss for these single-crystals is a significant part of the ferromagnetic resonance linewidth.