Ferromagnetic Resonance Absorption in a Nickel Single Crystal at Low Temperatures

The $g$-value and line width of the ferromagnetic resonance in nickel is found to be the same at 4°K as at room temperature. A small effect due to inhomogeneous magnetization in the skin depth, predicted by Kittel and Herring, has been observed. Values for the anisotropy constants at 4.2°K are $K_1=-8.3\mathrm{}\times {10}^5$ ergs/${\mathrm{cm}}^3$, $K_2=-1.4\mathrm{}\times {10}^5$ ergs/${\mathrm{cm}}^3$.