de Haas–van Alphen measurements of mixed valent CeSn3 (invited)

Abstract

We present the first Fermi surface measurements of a mixed valent metal, CeSn3. We find a complex Fermi surface with at least nine separate frequency branches. The measured effective masses are very large, ranging from 4.2 to 9.2. The results directly confirm the existence of coherent Bloch states in CeSn3 and strongly support an itinerant model of mixed valence based on hybridized energy bands. We compare the Fermi surface properties of CeSn3 to those of LaSn3, a non-mixed valent reference metal, and discuss how the comparison allows various proposed models of mixed valence to be tested. Preliminary band calculations using only exchange in the density functional are able to reproduce many of the qualitative features of the CeSn3 data.