Magnetic-Compton-scattering study of spin moments inUFe2

Spin moments were derived from the magnetic-Compton profile of ${\mathrm{UFe}}_2,$ which was measured using 59.38-keV circularly polarized synchrotron radiation from the Accumulation Ring Source at KEK, Japan. Although the net moment on the uranium site is no more than a tenth of a Bohr magneton, the individual spin and orbital moments, which are coupled antiparallel, are much larger and it is the spin moment that can be determined in magnetic-Compton scattering. The data have been analyzed in terms of the U $5f,$ Fe $3d$ and delocalized spin moments. The observed uranium-$5f$ spin moment is less than half (i.e., $<0.25\mathrm{}{\mu }_B$) and the diffuse spin moment more than double (i.e., $>0.20\mathrm{}{\mu }_B$) those predicted from theory. These values compare favorably with those deduced from neutron measurements of the total magnetization.