Kondo effect in a novel 5d quasi-skutterudite Yb3Os4Ge13

TL;DR

This study reports the synthesis, structural characterization, and electronic properties of a new Yb-based quasi-skutterudite compound, revealing Kondo behavior due to hybridization between Yb f-moments and Ge p-electrons.

Contribution

It introduces a novel 5d quasi-skutterudite Yb3Os4Ge13 and demonstrates its Kondo effect through experimental and theoretical analysis.

Findings

Yb3Os4Ge13 crystallizes in a cubic quasi-skutterudite structure.

Resistivity shows a crossover to Kondo-like behavior below 40 K.

Specific heat indicates strong electronic correlations with a large coefficient.

Abstract

We report the crystal growth of a new compound, Yb3Os4Ge13, by using a Bi-flux method. X-ray diffraction measurement shows that it crystallizes in the quasi-skutterudite-type caged structure with a cubic space group of Pm-3n (No. 223). Magnetic measurements reveal almost fully localized Yb f-moments above 120 K. The resistivity exhibits a crossover from metallic to insulating behavior with a logarithmic increase below ~ 40 K. The specific heat coefficient shows a rapid upturn below ~5 K and exceeds 2 J mol-1 K-2 at 2 K. Our experimental analysis and electronic band structure calculations demonstrate that Yb3Os4Ge13 exhibits the Kondo effect due to strong hybridization of the localized Yb f-moments with the p-electrons of the surrounding Ge-cages.