Synthesis, Crystal Structure, and Magnetic Properties of UFe5Sn

The UFe5Sn compound was synthesized by arc melting, followed by annealing at 800°C. The crystal structure was determined by single-crystal X-ray diffraction and refined to a residual value of R=0.035 (Rw=0.031). This compound crystallizes in the orthorhombic CeCu5Autype structure, space group Pnma, with lattice parameters a=8.082(3) ?, b=4.869(1) ?, and c=10.448(3) ?. Magnetization measurements were performed in the 5-300 K temperature range and under fields up to 5.5 T. The results indicate a weak ferromagnetic behavior at room temperature. Two magnetic anomalies are observed at 248 and 180 K, respectively, and the ferromagnetic character strongly increases below the highest temperature anomaly.