The origin of low magnetic anisotropy of UFe2: investigation of magnetization and magnetostriction of a U0.8Lu0.2Fe2 single crystal

Abstract Magnetization and magnetostriction were investigated on single crystals of UFe 2 and U 0.80 Lu 0.20 Fe 2 . The spin reorientation from the 〈1 1 1〉 to the 〈1 0 0〉 easy-magnetization axis as a consequence of the competition of cubic magnetocrystalline anisotropy constant K 1 0 and magnetoelastic contribution to the magnetic anisotropy Δ K 1 me was predicted and observed upon the dilution of the uranium sublattice of UFe 2 by non-magnetic Lu. Change of the anisotropy type is accompanied by the disappearance of spontaneous magnetostriction distortion (reaching 3×10 −3 in UFe 2 ) in U 0.8 Lu 0.2 Fe 2 . Nevertheless, measurements of magnetostriction in magnetic field confirmed that the diluted compound also has very a large magnetostriction constant λ 111 .