FUNCTIONAL DEPENDENCE OF THE IMAGINARY PART OF THE INITIAL PERMEABILITY OF THE YIG FAMILY OF FERRITES

This paper reports the experimental results of an investigation of the relationship between the composition of certain yttrium iron garnets (YIG) and the resulting initial permeability. A complimentary study of the compositional dependence of the real part of the permeability has been reported in the literature. A simple theory reported in a previous paper to explain the dependence of permeability on an applied quasistatic magnetic field predicts a dependence on the magnetization. With the previous work and the data to be reported here, the dependence of the complex permeability on magnetization has been confirmed for substitutions of calcium, vanadium, and indium. These substitutions were chosen to reduce the magnetization while maintaining the linewidth. A substitution of indium alone increases the magnetization above that of prototype YIG and agrees with the phenomenological theory for the imaginary part of permeability, but not for the real part.