Synthesis, structure, and magnetic characterization of Cr4US8

• At 1073 K Cr4US8 was synthesized and at 100 K its crystal structure was determined.
• The 3D structure comprises CrS6 octahedra with channels partially occupied by U.
• The magnetic behavior of Cr4US8 is complex.

The compound Cr4US8 has been synthesized at 1073 K and its crystal structure has been determined at 100 K. The structure is modulated with a two-fold commensurate supercell. The subcell may be indexed in an orthorhombic cell but weak supercell reflections lead to the monoclinic superspace group P21/c(α0γ)0s with two Cr sites, one U site, and four S sites. The structure comprises a three-dimensional framework of CrS6 octahedra with channels that are partially occupied by U atoms. Each U atom in these channels is coordinated by eight S atoms in a bicapped trigonal-prismatic arrangement. The magnetic behavior of Cr4US8 is complex. At temperatures above ~120 K at all measured fields, there is little difference between field-cooled and zero field-cooled data and χ(T) decreases monotonously with temperature, which is reminiscent of the Curie–Weiss law. At lower temperatures, the temperature dependence of χ(T) is complex and strongly dependent on the magnetic field strength.

Structure of Cr4US8 viewed down the a axis.Figure optionsDownload as PowerPoint slide