Interesting microwave ferrites of polycrystalline Y Gd I G´s with both octahedral and tetrahedral substitutions

The influences of simultaneous tetrahedral (aluminium) and octahedral substitutions (tin or indium) upon the magnetic and microwave properties of various YGdFe polycrystalline garnets have been studied. We have obtained interesting new materials with saturation magnetizations between 200 and 900 G which exhibit higher temperature stabilities of the magnetization than those of classical garnets. In addition they have fairly narrow gyromagnetic linewidths, weak dielectric losses and relatively high values of spin-wave linewidths. These properties, obtained by a judicious balance between both substitutions, make these materials suitable for applications in the lower frequency range of the microwave spectrum when high peak and average powers are needed.