Abstract
A microwave resonance apparatus for measuring K1/M , K2/M , geff , linewidth and magnetization as functions of pressure to 10000 atmos is described. At this pressure the volume of nickel ferrite is reduced by only 0.68% but significant changes in magnetic properties are observed. The results of measurements on Ni1−xCoxFe2O4(x = 0, 0.05, 0.10) are discussed in terms of Slonczewski's anisotropy theory.