Pressure Dependence of the Microwave Resonance Properties of Some Spinel and Garnet Ferrites

The anisotropy field, $g$ value, and linewidth of several spinel and garnet ferrites have been measured at $X$ band and room temperature as functions of hydrostatic pressure to ${10}^4$ kg/${\mathrm{cm}}^2$. The crystals studied include yttrium, ytterbium, and erbium iron garnet; magnesium ferrite (with different distributions of ${\mathrm{Mg}}^{2+}$ ions on $A$ and $B$ sites); and ${\mathrm{Ni}}_{1-z}{\mathrm{Co}}_z{\mathrm{Fe}}_2{\mathrm{O}}_4$ with $z=0, 0.05 \mathrm{and} 0.10$. The pressure dependence of magnetization was measured using magnetostatic mode methods in the narrow linewidth materials, yttrium iron garnet and magnesium ferrite.