Theoretical study of the ferromagnetism in UNi(2)
Electronic structure calculations for the ferromagnet UNi(2) in the hexagonal MgZn(2) structure (C14) are reported. In this treatment the uranium 5f electrons are considered as itinerant and are included in the self-consistent local-density calculations on the same footing as the other valence electrons. By adding the spin-orbit interaction and orbital polarisation to the Hamiltonian, a substantial cancellation between the spin and orbital moments on the uranium atom is obtained. This is in good qualitative agreement with neutron-scattering experiments and can be achieved only by inclusion of the orbital polarisation. From fixed-moment calculations, where the total magnetic moment is chosen to agree with data, a good agreement with the experimental uranium form factor is obtained. The contribution of the 6d electrons to the uranium magnetic form factor is particularly important for small Q vectors, which gives rise to a substantial improvement of the agreement with data when compared to an unconstrained fit where only 5f contributions to the uranium magnetic density are taken into account. The magnetism in UNi(2) is found to be driven by the uranium atoms, in contrast to the related system UFe(2) in which it is caused by the iron atoms.
Bibliographic Reference: Article: Physical Review B, Vol. 44 (1991) No. 17, pp. 9392-9399
Record Number: 199210415 / Last updated on: 1994-12-02
Original language: en
Available languages: en