Dependence of linewidth in hexagonal planar ferrites on angle between magnetostatic field and easy plane

Theoretical expressions for the linewidth of a single-crystal hexagonal planar sphere are compared with experimental results with the magnetostatic field taken at an arbitrary direction to the easy plane. It is shown that the overall line-width broadening favours the Bloch-Bloembergen form of damping, in comparison with the Landau-Lifshitz form. As the large anisotropy field is represented in a form identical to a shape-demagnetising field, the results indicate the dependence of the linewidth on the shape of the sample.