Magnetic anisotropy and spin reorientation in U2Co15Si2

Abstract: Field and temperature dependencies of the magnetization measured along the principal axes of a U2Co15Si2 single crystal show that this compound is a ferromagnet with a spontaneous magnetic moment of 14.8 μ B per formula unit (at 4.2K), located in the basal plane of the hexagonal crystal structure. A strong easy-plane magnetic anisotropy (K 1=−0.97MJm−3 at 4.2K) is attributed to the U sublattice because Lu2Co15Si2 exhibits easy-axis anisotropy with K 1=0.42MJm−3. The easy-plane anisotropy of U2Co15Si2 transforms to a cone of easy axes above 270K. The magnetization vector approaches the c-axis at 350K, and the compound has easy c-axis anisotropy up to the Curie temperature T C=601K. [Copyright &y& Elsevier]