Crystallographic disorder and magnetism in UPd 2− xSn

Abstract

The intermetallic compound UPd 2Sn has been shown in previous investigations to crystallize in an orthorhombic structure (space group Pnma). No indications for magnetic or superconducting transitions were found. However, if the Pd content is reduced, then, similar to UNi 2Sn, a structural transition occurs. We prepared UPd 1.85Sn and found it to crystallize as a Heusler compound in the MnCu 2Al-structure (space group Fm 3 m ). Now the system undergoes a transition into a disordered magnetic state at T mag ⋍ 28 K . Here, we present our measurements of the specific heat, susceptibility and muon relaxation of UPd 1.85Sn, and discuss the nature of the magnetic state in relation to the crystallographic structure.