Non-Fermi-liquid behavior in an undoped single crystal ofCeRh2Ga

Abstract

The measurements of specific heat $C,$ electrical resistivity \ensuremath{\rho}, magnetic susceptibility \ensuremath{\chi}, magnetization $M,$ Hall coefficient ${R}_{H},$ and thermoelectric power $S$ were performed on a ternary compound of ${\mathrm{CeRh}}_{2}\mathrm{Ga}$ which crystallizes in the triple-hexagonal ${\mathrm{Na}}_{3}\mathrm{As}$-type structure with the space group ${P6}_{3}\mathrm{cm}.$ ${\mathrm{CeRh}}_{2}\mathrm{Ga}$ remains in a paramagnetic state down to 1.2 K and exhibits a non-Fermi-liquid behavior. The specific heat divided by temperature $C/T$ shows a ${T}^{\ensuremath{-}1+\ensuremath{\lambda}}$ power-law temperature dependence with $\ensuremath{\lambda}=0.15$ (from 7 K to the lowest measured temperature 1.2 K). ${\ensuremath{\chi}}_{\ensuremath{\perp}}(H\ensuremath{\perp}c)$ exhibits the same power-law behavior up to 50 K with $\ensuremath{\lambda}=0.21,$ while ${\ensuremath{\chi}}_{\ensuremath{\parallel}}$ $(H\ensuremath{\parallel}c)$ shows the power-law behavior in the restricted temperature range up to 20 K with $\ensuremath{\lambda}=0.52.$ At $T=1.8\mathrm{K}$ and $H<1\mathrm{T},$ $M$ varies linearly with $H;$ above 1 T, $M$ could be described by $M=\mathrm{const}{+H}^{\ensuremath{\lambda}}$ with $\ensuremath{\lambda}=0.59$ and 0.20 for $H\ensuremath{\parallel}c$ and $H\ensuremath{\perp}c,$ respectively. The power-law dependence behavior is consistent with the Griffiths phase scenarios. \ensuremath{\rho} increases linearly with decreasing temperature below 4 K, also signaling non-Fermi-liquid behavior. ${R}_{H}$ shows a $1/T$ dependence below 20 K. $S$ shows a $\mathrm{ln}T$ dependence between 4 and 20 K, followed by a negative minimum at $\ensuremath{\sim}3\mathrm{K}.$ The low-temperature unconventional behaviors in ${R}_{H}$ and $S$ for ${\mathrm{CeRh}}_{2}\mathrm{Ga}$ may be related to the non-Fermi-liquid anomalies observed in the specific heat and magnetic susceptibility.