Magnetic Moments and Unpaired-Electron Densities in CoPt3

A polarized-neutron investigation of the ferromagnetic alloy Co${\mathrm{Pt}}_3$ in various degrees of chemical order is presented. The magnetic moments of the two components have been determined; that of the cobalt is $1.64\pm 0.04{\mu }_B$, and that of the platinum $0.26\pm 0.02{\mu }_B$ in the fully ordered material. The experimental form factors of platinum and cobalt were measured and it is shown that they are in fair agreement with recent theoretical calculations. A Fourier inversion of the data was also carried out to show the $t_{2g}$ character of the cobalt $d$ electrons of this alloy.