We report neutron-diffraction results on UCuSn which crystallizes in the orthorhombic P 21 cn structure. This compound undergoes two magnetic transitions around TN =62 K and TM =25 K. At T=52 K, UCuSn exhibits a noncollinear arrangement of uranium moments of ∼1.5 μB U -atom with components in all three principal directions. Our diffraction data provide further evidence that the transition around 25 K is indeed magnetic in origin, although our refinements did not lead to a conclusive answer on its exact nature.
Bibliographical noteFunding Information:
This work has been supported by the NSF (Grant No. DMR-0094241), the Basic Energy Sciences Program of the Department of Energy, and the Department of Commerce. Work at the NIST utilized facilities supported in part by the National Science Foundation under Agreement No. DMR-0454672. The authors thank E. Fernandez for her help with some of the figures.