Anisotropy and FMR in cobalt doped YIG films

The temperature dependence of FMR was measured on thin LPE films YIG:Co/sub 0.03/Ca/sub 0.3/ and YIG:Co/sub 0.06/Ge/sub 0.65/Ca/sub 0.7/. The measured value of K/sub 1/ was used to estimate Co/sup 2+/(a) and Co/sup 3+/(d) content. For YIG:Co,Ge,Ca the large increase of FMR linewidth towards lower temperatures was observed. The angular dependence of linewidth was compared with the calculation based on the inhomogeneous anisotropy field model. It is suggested that the low temperature increase of /spl Delta/II is caused predominantly by fluctuations in the cubic anisotropy field, having its origin in an inhomogeneous distribution of Ca/sup 2+/ ions within the film.<
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