Kondo Sidebands in CeAl3and Related Pseudobinary Compounds

The temperature dependence of the electrical resistivity (1.3-300 °K) has been studied for the isomorphous compounds ${\mathrm{Ce}}_{1-x}{\mathrm{La}}_x{\mathrm{Al}}_3$, ${\mathrm{Ce}}_{1-x}{\mathrm{Y}}_x{\mathrm{Al}}_3$, and ${\mathrm{Ce}}_{1-x}{\mathrm{Th}}_x{\mathrm{Al}}_3$. In these compounds, one or two maxima have been observed in the $\rho -\mathrm{v}\mathrm{s}-T$ curve. An analysis of the experimental results is presented in terms of the Kondo sideband theory, which describes Kondo exchange scattering of the conduction electrons in the presence of localized moments whose ground-state manifold is split owing to the presence of crystalline fields. It is shown that the changes observed in $\rho$ behavior for Ce${\mathrm{Al}}_3$ upon replacement of Ce by La, Y, or Th can be correlated with changes in the crystal field parameters, and in the case of Th also with changes in the density of states of the conduction electrons.