Kondo Effect inLa1−xCexAlloys under Pressure

The low-temperature electrical resistance of ${\mathrm{La}}_{1-x}{\mathrm{Ce}}_x$ alloys in both the fcc and the dhcp phase has been measured under pressure. Between normal pressure and 19 kbar the resistance always exhibited a minimum at $T_{min}$, which initially increased slightly under pressure, but remained constant above 7 kbar. The resistance $R\mathrm{}\left(T\right)\mathrm{}$ for $T<\mathrm{}{T}_{min}$ varied as $\ln T$ down to the superconducting transition temperature $T_c$ or the limiting measuring temperature (1.3°K). The slope, $\frac{-dR\mathrm{}\left(T\right)\mathrm{}}{d\ln T}$, varied appreciably and nonmonotonically with pressure; the relationship between the depression of $T_c$ and $\frac{-dR\mathrm{}\left(T\right)\mathrm{}}{d\ln T}$ as a function of pressure is discussed.