Evidence for a Common Physical Description of Non-Fermi-Liquid Behavior in Chemically Substituted<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi mathvariant="italic">f</mml:mi></mml:math>-Electron Systems

Abstract

The non-Fermi-liquid (NFL) behavior observed in the low temperature specific heat $C(T)$ and magnetic susceptibility $\ensuremath{\chi}(T)$ of many chemically substituted $f$-electron systems is analyzed within the context of a recently developed theory based on Griffiths' singularities. Measurements of $C(T)$ and $\ensuremath{\chi}(T)$ in the systems ${\mathrm{Th}}_{1\ensuremath{-}x}{\mathrm{U}}_{x}{\mathrm{Pd}}_{2}{\mathrm{Al}}_{3}$, ${\mathrm{Y}}_{1\ensuremath{-}x}{\mathrm{U}}_{x}{\mathrm{Pd}}_{3}$, and ${\mathrm{UCu}}_{5\ensuremath{-}\mathrm{x}}{\mathrm{M}}_{x}$ ( $M\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}\mathrm{Pd},\mathrm{Pt}$) are found to be consistent with $C(T)/T\ensuremath{\propto}\ensuremath{\chi}(T)\ensuremath{\propto}{T}^{\ensuremath{-}1+\ensuremath{\lambda}}$ predicted by this model with $\ensuremath{\lambda}&lt;1$ 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.