Evidence for a Common Physical Description of Non-Fermi-Liquid Behavior in Chemically Substitutedf-Electron Systems

The non-Fermi-liquid (NFL) behavior observed in the low temperature specific heat $C\left(T\right)$ and magnetic susceptibility $\chi \left(T\right)$ of many chemically substituted $f$-electron systems is analyzed within the context of a recently developed theory based on Griffiths' singularities. Measurements of $C\left(T\right)$ and $\chi \left(T\right)$ in the systems ${\mathrm{Th}}_{1-x}{\mathrm{U}}_x{\mathrm{Pd}}_2{\mathrm{Al}}_3$, ${\mathrm{Y}}_{1-x}{\mathrm{U}}_x{\mathrm{Pd}}_3$, and ${\mathrm{UCu}}_{5-\mathrm{x}}{\mathrm{M}}_x$ ( $M=\mathrm{Pd},\mathrm{Pt}$) are found to be consistent with $C\left(T\right)/T\propto \chi \left(T\right)\propto T^{-1+\lambda }$ predicted by this model with $\lambda <1\mathrm{}$ in the NFL regime. These results suggest that the NFL properties observed in a wide variety of disordered $f$-electron systems can be described within the context of a common physical picture.