Magnetic properties of U2(Fe1−xCox)13.6Si3.4 single crystals

Abstract Magnetization was measured on single crystals U 2 (Fe 1− x Co x ) 13.6 Si 3.4 (0⩽ x ⩽1) grown by Czochralski method. Compounds with x up to 0.95 exhibit the easy-plane magnetic anisotropy. The anisotropy constants K 1 and K 2 for x up to ∼0.8 are high enough to suggest a U contribution to the anisotropy, i.e., a magnetic state of U. Both K 1 and K 2 behave non-monotonously with increasing x , K 2 changes sign at x =0.3. We suppose that U becomes non-magnetic above x =0.9. The weakening of the anisotropy and the change of its type at high Co content are attributed to the 3d-metal sublattice.