Effect of Rare-Earth Impurities on the Peak Power Capability of Garnet Type Low-Field Microwave Devices

From recent work revealing that rare-earth ions of fixed concentration in a garnet ferrimagnet give rise to an additional spin-wave line-width term that is inversely proportional to the saturation magnetization of the host garnet, it is shown that rare-earth impurities found in commercial yttrium end gadolinium oxides used for producing ferrimagnets can contribute to unwanted variations in the peak power handling capacity of low-field microwave devices.