Low Temperature Thermoelectric Power of Ce(Pd $$_{1-x}$$ 1 - x Cu $$_x$$ x ) $$_2$$ 2 Si $$_2$$ 2

Abstract

We present the thermoelectric power $$S(T)$$ of the Ce(Pd $$_{1-x}$$ Cu $$_x$$ ) $$_2$$ Si $$_2$$ alloy for temperatures $$1.5\,\mathrm{K}<T<300\,$$ K. We observe three characteristic features across the $$0<x<1$$ substitution range: two positive maxima and a negative minimum, that are typical for Ce compounds that display, or lie close to, magnetism. Our analysis of the data shows that the high- $$T$$ maximum is related to the Kondo effect on excited crystal-field levels, but that the low- $$T$$ one cannot be simply associated with the Kondo scale, $$T_\mathrm{K}$$ . We speculate that disorder induced by alloying can be at the origin of this discrepancy and can also be responsible for the low $$S(T)$$ measured at low temperatures in the $$0.2<x<0.8$$ concentration range. We have extended electrical resistivity measurements on Ce(PdCu)Si $$_2$$ ( $$x=0.5$$ ) down to $$T\sim 40$$ mK in applied fields as high as $$16$$ T.