Kondo effect in a novel 5d quasi-skutterudite Yb$_{3}$Os$_{4}$Ge$_{13}$
ORAL
Abstract
We report the crystal growth of a new compound, Yb$_{3}$Os$_{4}$Ge$_{13}$, by using a Bi-flux method. It crystalizes 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 $\sim$ 40 K. The specific heat coefficient shows a rapid upturn below $\sim$ 5 K and exceeds 2 J mol$^{-1}$ K$^{-2}$ at 2 K. Our experimental analysis and electronic band structure calculations demonstrate that Yb$_{3}$Os$_{4}$Ge$_{13}$ exhibits the Kondo effect due to strong hybridization of the localized Yb $f$-moments with the $p$-electrons of the surrounding Ge-cages.
–