Chemical bonding and physical properties of Yb5Bi3

Abstract

The binary compound Yb5Bi3 was synthesized by reaction of the elements in a sealed Ta container. Its crystal structure was determined from single-crystal X-ray diffraction data: ß-Yb5 Sb3 -type, space group Pnma, Pearson code oP32, a = 12.6375(6), b = 9.7243(4), c = 8.4117(5) Å, V = 1033.72(9) Å3, Z = 4, Rgt(F) = 0.028, wRref(F2) = 0.069, T = 290 K. Band structure calculations and analysis of the chemical bonding suggest mainly ionic interactions in the crystal structure and a possible presence of ytterbium in two valence states Yb2+ and Yb3+. The magnetization measurements showed that at low temperatures Yb5Bi3 contains ytterbium exclusively in the 4f14 configuration without fluctuations to the Yb 4f13 configuration up to 400 K. From the Yb-LIII X-ray absorption spectroscopy data the effective valence of ytterbium was found to be 2.11 (89 % of Yb in 4f14 configuration). © 2007 Verlag der Zeitschrift für Naturforschung.