A dilute limit of CeAl${}_3$: Emergence of the single-ion Kondo scaling

Abstract

Strongly diluted Ce${}_x$La${}_{1-x}$Al${}_3$ alloys have been studied by the low temperature specific heat in order to elucidate the mechanism that determine their ground state. All alloys with Ce concentrations of $0.0005\le x\le 0.1$ show a $S=1/2$ Kondo behavior. However, the single-ion scaling is observed only below $x=0.01$. The true single-ion Kondo temperature is small, 0.2 K, and is identical to that for dilute CeAl${}_2$. It is about 20 times smaller than that for CeAl${}_3$, indicating that intersite interactions facilitate Kondo-screening in CeAl${}_3$ and concentrated Ce${}_x$La${}_{1-x}$Al${}_3$ alloys.