MAGNETIC-STRUCTURES OF URANIUM-COMPOUNDS - EFFECTS OF RELATIVITY AND SYMMETRY

We report results of calculations that explain the noncollinear magnetic structures observed in U3P4 and U2Pd2Sn in the itinerant-electron picture. We use the local approximation to spin-density functional theory and the augmented spherical wave method incorporating spin-orbit coupling (SOC) and noncollinear moment arrangements. We show how the relativistic effect of SOC and the different symmetry properties of U3P4 and U(2)Pd(?)2Sn cooperate, leading in the case of U3P4 to ferromagnetic and in the case of U2Pd2Sn to antiferromagnetic noncollinear structures.