Structural studies and magnetism of Dy6Ni2.43Sn0.5 stannide

Intermetallic compound Dy6Ni2.43Sn0.5 was prepared by arc melting and annealing at 873 K. It was characterized by X-ray powder diffraction, differential thermal analysis, and electron probe microanalysis. The crystal structure of low temperature Dy6Ni2.43Sn0.5 phase belongs to the orthorhombic Ho6Co2Ga structure type (space group Immm, a = 0.93116(1) nm, b = 0.94993(1) nm, c = 0.98947(1) nm). Crystal structure refinements showed the deviation from the ideal 6:2:1 stoichiometry corresponding to the formula Dy6Ni2.43Sn0.5. It exhibits a sequence of magnetic phase transitions; antiferromagnetic ordering sets in at 60 K, while further order-order magnetic phase transitions take place at lower temperatures

Synthesis and Study of New Hydrides Based on f-Metals

Katedra fyziky kondenzovaných látekDepartment of Condensed Matter PhysicsFaculty of Mathematics and PhysicsMatematicko-fyzikální fakult

New U2T2X Hydrides

Abstract is not availableJRC.E.6-Actinides researc

Structure and Magnetism of Thin UX Layers

US layers (thickness 0.1 0.3 m) were prepared by sputter deposition from US target in Ar atmosphere at temperatures 298 573 K. For US thin films, magnetism tends to be suppressed comparing to the bulk US, which is a band ferromagnet with TC = 177 K. TC decreases down to 85 105K for the layers deposited at room temperature (depending on the deposition parameters) and increases with the increase of the temperature of substrate. Spontaneous magnetization in the ordered state is suppressed considerably for the deposited layers: down to 0.1B/f.u. or less for all samples studied (compare with 1.55 B/f.u. for bulk US). The changes in the magnetic properties are correlated with the microstructure of the films. Microstructure studies indicated that the US thin films contain a mixture of “nanocrystalline” and “amorphous” parts. The crystallite size in the nanocrystalline parts is approximately 100 A . In all samples, a compressive residual stress was observed, which caused a strongly anisotropic lattice deformation with the easy deformation direction (1 1 1). The compressive residual stress was below −3GPa in most samples. Results are compared with UN layers synthesized by reactive sputtering.JRC.E.6-Actinides researc

Peculiarities of U2T2X hydrides

U2Ni2Sn belongs to a large group of U2T2X compounds which are very sensitive to hydrogen absorption. U2Ni2SnH1.8 and U2Ni2SnD1.8 exhibit similar magnetic behaviour they order antiferromagnetically at , which is much higher than in U2Ni2Sn. Deuterium lattice sites were determined by neutron diffraction. Uranium magnetic moments lie in the basal plane of the tetragonal structure