Saturation Effects in the Magnetic Resonance of Paramagnetic Impurities in Metals

The saturation of the magnetic resonance of paramagnetic impurities in metallic hosts is investigated. The earlier work of N. Bloembergen is extended to metallic films of finite thickness. The absorption line shape and its derivative with respect to the static applied field are calculated. Comparison is made with the corresponding results for an insulating host, and suggestions are given as to the way in which saturation effects might be identified.