Low Temperature Electronic and Magnetic Properties of CePd$_{3}M_{x}$

The intermediate valence compound CePd$_{3}$ is a strong candidate for low temperature thermoelectric applications due to its unusually large Seebeck coefficient which peaks at approximately 115 $\mu $V/K near 125K. This phenomenon results from a sharp peak in the density of states near the Fermi level due to the hybridization of conduction electrons with those in the partially occupied cerium f-shell, thus making the system highly sensitive to changes in the average cerium valence state. We have systematically studied the structural and thermoelectric properties of various CePd$_{3}M_{x}$ compounds, where $M$ is an s- or p-block element and 0 $<$ x $<$ 0.1, in order to explore the effects of such partial filling on the cerium valence. The results of X-ray diffraction, Seebeck coefficient, and magnetic susceptibility measurements are reported. We have found that incorporating $M$ elements of various valence configurations has similar effects on the electronic and magnetic properties as changing the $M$ concentration, thus establishing an effective new mechanism for tailoring the thermoelectric properties of the system. \newline