Polarized neutron diffraction study of UNi2

A polarized neutron diffraction study of the hexagonal UNi2 was performed. The magnetization of this weak ferromagnet (with Curie temperature Tc=21 K and saturation moment μs ≅ 0.08 μB per formula unit) is essentially due to the 5f electrons of the uranium. The 5f form factor is most unusual for uranium, with a pronounced maximum at about (sin θ)/λ ≅ 0.2 A-1 indicating the presence of a very large orbital moment. This is the first experimental evidence of a large orbital magnetization density in an itinerant electron ferromagnet. (orig.)