Electronic structure of ferromagnetic Ni-Al solid solutions

Abstract

The $K$ and $L_{\mathrm{III}}$ x-ray absorption edges of Ni-Al alloys have been measured in the fcc solid-solution region. The absorption spectra recorded did not show any changes, due to the addition of aluminum, in the region of the spectra corresponding to unoccupied nickel $3d$ states. This result is in agreement with other measurements of nickel-rich solid solutions, and indicates that the addition of aluminum to nickel decreases the nickel magnetic moment, not by a filling of empty $3d$ states, but by a rearrangement of the spin-up and spin-down populations of the $3d$ subbands in apparent violation of Hund's rule.