Crystallographic and magnetic properties of UPdSn

• Published in: Journal of applied physics 1993-05, Vol.73 (10), p.6072-6074
• Main Authors: JOHNSON, S. W, ROBINSON, R. A, NAKOTTE, H, BRÜCK, E, DE BOER, F. R, LARSON, A. C
• Format: Article
• Language: English
• Subjects: 360104 > Metals & Alloys-- Physical Properties; ACTINIDE COMPOUNDS; ALLOYS; Applied sciences; COHERENT SCATTERING; Condensed matter: electronic structure, electrical, magnetic, and optical properties; CRYSTAL STRUCTURE; CRYSTALS; DIFFRACTION; DOMAIN STRUCTURE; Exact sciences and technology; INTERMETALLIC COMPOUNDS; MAGNETIC PROPERTIES; Magnetic properties and materials; MATERIALS SCIENCE; Metals. Metallurgy; MONOCRYSTALS; NEUTRON DIFFRACTION; PALLADIUM COMPOUNDS; PHASE TRANSFORMATIONS; PHYSICAL PROPERTIES; Physics; SCATTERING; Spin arrangements in magnetically ordered materials (including neutron and spin-polarized electron studies, synchrotron-source x-ray scattering, etc.); TIN COMPOUNDS; TRANSITION ELEMENT COMPOUNDS 360102 > Metals & Alloys-- Structure & Phase Studies; URANIUM COMPOUNDS
• ISSN: 0021-8979; 1089-7550
• DOI: 10.1063/1.353473

A single crystal of the intermetallic compound UPdSn has been studied by means of neutron diffraction using the white-beam Laue diffractometer (single-crystal diffractometer) at the Los Alamos spallation neutron source. Data were taken in the paramagnetic phase at 55 K and just below the Néel point at 37 K. The crystallographic data refine well within the space group P63mc and confirm the results obtained previously on powders, namely that the Pd and Sn atoms are ordered. At low temperature, UPdSn undergoes two phase transitions at 40 and 25 K to complicated noncollinear antiferromagnetic structures. All three pairs of magnetic domains are observed, in roughly equal populations, in the intermediate-temperature orthorhombic magnetic structure (phase I). A uranium moment of 0.863μB and canting angles φ=56.51° and θ=21.42° were obtained, in reasonable agreement with previous powder neutron data for this temperature. The observed form factor yields an orbital-to-spin moment ratio −μL/μS=2.6 which is characteristic of the trivalent f3 configuration.