On the Gyromagnetic Ratio and Spectroscopic Splitting Factor of Ferromagnetic Substances

Abstract

A discussion is given of the connection between the results of microwave resonance absorption experiments and gyromagnetic ratio experiments on ferromagnetic substances. A review of the experimental data indicates that the microwave experiments usually give $g>2$, while gyromagnetic measurements usually give values of the related quantity ${g}^{\ensuremath{'}}$ which are 2. The analogous situation obtaining in paramagnetic salts is explained by means of a simple example, and the application of the argument to ferromagnetic substances is indicated. The validity of the use of $g$ in the macroscopic equations of motion in the resonance experiment is justified as a consequence of the approximate mutual cancellation of the orbital and lattice angular momenta. A critical discussion is given of other attempts to explain the $g\ensuremath{\ne}{g}^{\ensuremath{'}}$ effect.