Region of Quantum Critical Behavior in Ce(Ru$_{1-x}$Rh$_{x})_{2}$Si$_{2}$

ORAL

Abstract

The magnetic phase diagram of Ce(Ru$_{1-x}$Rh$_{x})_{2}$Si$_{2}$ is quite rich, with a spin density ordering temperature approaching T=0 around x$_{QCP }$= 0.4 and with - from the Rh rich side where T$_{N}$ of CeRh$_{2}$Si$_{2}$ is 36 K - a long range, local moment ordering temperature approaching T=0 at approximately x$_{QCP}$ = 0.6. Specific heat data down to 0.04 K for a number of compositions indicate a \textit{region} of non-Fermi liquid behavior between x=0.4 and 0.6 associated with the two quantum critical points. The nature of the nFl temperature dependence in the specific heat changes from Moriya-like weak spin fluctuation behavior at the Ru rich side to strong fluctuation, C/T $\propto $logT behavior at the Rh rich end. How this smooth progression of behavior with increasing x provides insights into our understanding of non-Fermi liquid behavior in general will be discussed. The disagreement in the literature over whether C/T is Moriya-like or follows logT at x=0.5 is resolved in favor of the former temperature dependence.

*Work at Florida supported by the US DOE, contract no. DE-FG05-86ER45268.

Authors

  • G.R. Stewart

  • J.S. Kim

  • D.J. Mixson

  • D. Burnette

    • Dept. of Physics, Univ. of Florida