Valence effect on the thermopower of Eu systems


We investigated the thermoelectric transport properties of EuNi2P2 and EuIr2Si2 to evaluate the relevance of Kondo interaction and valence fluctuations in these materials. While the thermal conductivities behave conventionally, the thermopower curves exhibit large values with pronounced maxima as typically observed in Ce- and Yb-based heavy-fermion materials. However, neither the positions of these maxima nor the absolute thermopower values at low temperature are in line with the heavy-fermion scenario and the moderately enhanced effective charge carrier masses. Instead, we may relate the thermopower in our materials to the temperature-dependent Eu valence by taking into account changes in the chemical potential. Our analysis confirms that valence fluctuations play an important role in EuNi2P2 and EuIr2Si2.

Europium, Europium compounds, Iridium compounds, Nickel compounds, Silicon, Silicon compounds, Temperature, Thermal conductivity, Thermoelectric power, Effective charge, Heavy fermion, Kondo interactions, Low temperatures, Temperature dependent, Thermoelectric transport properties, Valence fluctuations, Phosphorus compounds
Stockert, U., Seiro, S., Seiro, S., Caroca-Canales, N., Hassinger, E., Hassinger, E., & Geibel, C. (2020). Valence effect on the thermopower of Eu systems (Version publishedVersion, Vol. 101). Version publishedVersion, Vol. 101. College Park, MD : American Physical Society.