Сrystal structure and physical properties of the new ternary antimonides Ln3Pd 8Sb 4 ( Ln=Y, Gd, Tb, Dy, Ho, Er, Tm)

Abstract

The ternary antimonides Ln 3Pd 8Sb 4 ( Ln=Y, Gd, Tb, Dy, Ho, Er, Tm) have been synthesized for the first time. The crystal structure of Er 3Pd 8Sb 4 has been solved from the X-ray single crystal data: own type structure, space group Fm3¯ m, a=1.3050(1) nm, R F=0.0484, R W=0.0524 for 17 free parameters and 401 reflections with F( hkl)>4 σ( F). The structure of Er 3Pd 8Sb 4 can be viewed as a ternary ordered version of the Sc 11Ir 4-type. The lattice parameters of the isotypic compounds Ln 3Pd 8Sb 4 ( Ln=Y, Gd, Tb, Dy, Ho, Tm) have been refined from the X-ray powder diffraction data. The magnetic and electrical properties of the compounds Ln 3Pd 8Sb 4 ( Ln=Tb, Ho, Er) have been studied down to 1.75 K. The Ho- and Er-based phases have been found to order antiferromagnetically at 2.5 and 2.0 K, respectively. For all three compounds, the magnetic susceptibility follows in the paramagnetic region the Curie–Weiss behavior with the effective magnetic moments close to the respective free trivalent ion values. All three antimonides studied exhibit metallic character of the electrical conductivity.