Crystal growth and composition-property relationship ofCe3Pd20Si6single crystals

Abstract

To elucidate the discrepancies in low-temperature data reported on the quantum critical heavy fermion compound ${\text{Ce}}_{3}{\text{Pd}}_{20}{\text{Si}}_{6}$ and reveal the compound's intrinsic properties, single crystals of varying stoichiometry were grown by various techniques---from the melt and from high-temperature solutions using fluxes of various compositions. The resulting stoichiometry of the crystals as well as their physical properties show sizable dependence on the different growth techniques. The Ce content $\ensuremath{\Delta}\text{Ce}$ varies by more than $3\text{ }\text{at}\text{.}\text{ }%$ among all grown single crystals. We have revealed a systematic dependence of the residual resistance ratio, the lattice parameter, the (lower) phase-transition temperature ${T}_{L}$, and the maximum in the temperature dependent electrical resistivity ${T}_{max}$ with $\ensuremath{\Delta}\text{Ce}$. This clarifies the sizable variation in the values of ${T}_{L}$ reported in the literature. We discuss the physical origin of the observed composition-property relationship in terms of a Kondo lattice picture. We predict that a modest pressure can suppress ${T}_{L}$ to zero and thus induce a quantum critical point.