Crystal structure and properties of Yb₅Ni₄Ge₁₀

Abstract

The new compound Yb₅Ni₄Ge₁₀ was obtained as single crystals in high yield from reactions run in liquid indium. Single-crystal X-ray diffraction data showed that it crystallizes in the Sc₅Co₄Si₁₀ structure type in the tetragonal space group P4/mbm. The structure is a three-dimensional framework of [Ni₄Ge₁₀] atoms with voids filled by Yb atoms. The Ni and Ge atoms form pentagons, hexagons, and octagons along the ab one-dimensional plane, which are interconnected along the c axis via Ni–Ge–Ni zigzag chains. Magnetic measurements reveal that Yb₅Ni₄Ge₁₀ crystals show paramagnetic behavior with a lack of long-range magnetic ordering down to 2 K. The magnetic susceptibility deviates from the Curie–Weiss law below 100 K, presumably because of crystal field effects from Yb³⁺ ions. In specific heat measurements, the compound exhibits non-Fermi-liquid-like behavior at low temperatures.