Ferromagnetic Resonance Linewidth Models for Perpendicular Media
Robert D. McMichael
Ferromagnetic resonance linewidth in pendicular recording media is modeled with inhomogeneous uniaxial anisotropy field Hu and with tilting of the easy axes from the film normal. The linewidth is calculated using both a local resonance model and a classical equivalent of the two-magnon model. Linewidth due to Hu variations and linewidth due to easy axis tilting are shown to produce very different angular dependence, and when the two-magnon models are valid, the linewidth is also shown to depend on inter-granular exchange coupling.