Kondo effect in Y-rich alloys containing a Ce impurity

Sugawara et al. have found that Ce impurities in some nonmagnetic rare earth hosts exhibit the Kondo effect. Maple and Wittig have shown that when pressure is applied to Y--Ce, the Kondo effect disappears, assumedly because the 4f level is driven from below to above the Fermi level. In the work reported here, alloy hosts of Y/sub x/La/sub 1-x/ are used to get the slope of the Kondo resistivity as a function of atomic volume for samples containing 2 atomic percent Ce impurity. The slope of the rho vs ln T, (drho/d lnT) varies markedly with atomic volume and shows a sharp peak near x = 0.95. Furthermore, by using Y- -Lu host alloys the Kondo effect will disappear at the atomic volume calculated for the Maple and Wittig result. (auth)