External susceptibility tensor of magnetised ferrite ellipsoid in terms of uniform-mode ellipticity

In the paper, the components of the external susceptibility tensor in finite ellipsoidal shapes are given in terms of the uniform-mode ellipticity. This notation besides introducing the uniform-mode ellipticity simply relates the form of the external susceptibility tensor to the internal one. Measurement of the uniform-mode ellipticity provides an alternative method to the usual Kittel resonance method by which the properties of single-crystal ferrites can be obtained. The uniform-mode ellipticity is also important because it is responsible for lineshape asymmetry at low frequencies. A final advantage is that it allows a single rule for introducing the Landau-Lifshitz form of damping into the loss free components of both the internal and external susceptibilities. The paper concludes with experimental results for a hexagonal single-crystal ferrite with planar anisotropy which is biased in the easy plane.