Orbital and Spin Magnetization in Fe-Co, Fe-Ni, and Ni-Co

Abstract

The effective electronic orbital contribution ${M}_{0}$ and the effective electronic spin contribution ${M}_{s}$ to the spontaneous magnetization ${M}_{t}$ for binary alloys of Fe, Co, and Ni are determined from Scott's measured magnetomechanical ${g}^{\ensuremath{'}}$-factors using the relations $\frac{{M}_{0}}{{M}_{t}}=\frac{(2\ensuremath{-}{g}^{\ensuremath{'}})}{{g}^{\ensuremath{'}}}$ and $\frac{{M}_{s}}{{M}_{t}}=\frac{2({g}^{\ensuremath{'}}\ensuremath{-}1)}{{g}^{\ensuremath{'}}}$ where ${g}^{\ensuremath{'}}$ is assumed to be independent of the strength of the magnetic field and the temperature. It is believed that $\frac{{M}_{0}}{{M}_{t}}$ has several-fold greater accuracy when determined from the ${g}^{\ensuremath{'}}$ factors than when determined from ferromagnetic-resonance $g$ factors. In terms of the Bohr magneton ${\ensuremath{\mu}}_{B}$, the orbital magnetic moments for the pure elements at 300\ifmmode^\circ\else\textdegree\fi{}K are: for iron, $(0.0918\ifmmode\pm\else\textpm\fi{}0.0033){\ensuremath{\mu}}_{B}$ (4.22% of ${M}_{t}$); for cobalt, $(0.1472\ifmmode\pm\else\textpm\fi{}0.0034){\ensuremath{\mu}}_{B}$ (8.81% of ${M}_{t}$); and for nickel, $(0.0508\ifmmode\pm\else\textpm\fi{}0.0012){\ensuremath{\mu}}_{B}$ (8.92% of ${M}_{t}$). The ${M}_{s}$ values for the fcc phases of the alloys agree well with those reported by Meyer and Asch from their $g$-factor data. For these alloys, ${M}_{0}$ is much more sensitive to the crystalline structure than ${M}_{s}$ and ${M}_{t}$ are. The relationship ${g}^{\ensuremath{'}\ensuremath{-}1}+{g}^{\ensuremath{-}1}=1$ holds for Fe-Ni and Fe-Co alloys (with the exception of one point) within the accuracy of the $g$-factor measurements (\ensuremath{\sim}0.1-1.0%).