Open Access Publications from the University of California

## Two energy scales and slow crossover in YbAl3

• Author(s): Lawrence, J.M.;
• Ebihara, T.;
• Riseborough, P.S.;
• Booth, C.H.;
• Pagliuso, P.G.;
• Sarrao, J.L.;
• Thompson, J.D.
• et al.
Abstract

We present results for YbAl$_3$ which show that the susceptibility $\chi(T)$, 4f occupation number $n_f(T)$ and the entropy $S(T)$ exhibit a slow crossover between the Fermi liquid and local moment regimes. In addition both $\chi(T)$ and the linear specific heat coefficient $\gamma = C/T$ exhibit low temperature peaks that imply that in addition to the Kondo scale ($T_K$ $\approx$ 500K) there is a second low temperature scale ($T_coh$ ^M$\approx$ 50K) for the onset of coherence. We discuss these results in the context of Nozieres' exhaustion in the Anderson lattice.