The γ→α isostructural transition in the Ce0.9−xLaxTh0.1 system is measured as a function of La alloying using specific heat, magnetic susceptibility, resistivity, thermal expansivity/striction measurements. A line of discontinuous transitions, as indicated by the change in volume, decreases exponentially from 118 K to close to zero with increasing La doping and the transition changes from being first-order to continuous at a critical concentration 0.10≤xc≤0.14. At the tricritical point, the coefficient of the linear T term in the specific heat γ and the magnetic susceptibility start to increase rapidly near x = 0.14 and gradually approaches large values at x=0.35 signifying that a heavy Fermi-liquid state evolves at large doping. Near xc, the Wilson ratio, RW, has a value of 3.0, signifying the presence of magnetic fluctuations. Also, the low-temperature resistivity shows that the character of the low-temperature Fermi-liquid is changing.
@article{arxiv.cond-mat/0608301,
title = {Tricritical Phenomena at the Cerium $\gamma \to \alpha$ Transition},
author = {J. C. Lashley and A. C. Lawson and J. C. Cooley and B. Mihaila and C. P. Opeil and L. Pham and W. L. Hults and J. L. Smith and G. M. Schmiedeshoff and F. R. Drymiotis and G. Chapline and S. Basu and P. S. Riseborough},
journal= {arXiv preprint arXiv:cond-mat/0608301},
year = {2009}
}