Nonuniform internal field in planar ferrite elements

The distribution of the static internal field and magnetization is calculated here numerically for rectangular ferrite platelets. Calculations are performed for the case of YIG (Y3Fe5O12) as model material, assuming that the dc bias field is applied perpendicular or parallel to the plane of the platelet. The extent of the nonuniform region of the internal field and dc magnetization around the edges and corners depends strongly on the applied field. The inhomogeneity of the internal field and the magnetization leads to extra linewidth broadening and the early onset of instabilities at increased power.