Study of low carrier density heavy fermion Ce$_{3}$Au$_{3}$Sb$_{4}$*

Ce$_{3}$Au$_{3}$Sb$_{4}$ is a narrow gap semiconductor with a well localized Ce$^{3+}$ state. The specific heat measurements, however, show a Kondo impurity like behavior with a large increase of the specific heat coefficient at low temperature, suggesting a heavy fermionic character in this low carrier concentration system. Magnetic susceptibility, resistivity, and specific heat data will be shown for single crystal Ce$_{3}$Au$_{3}$Sb$_{4}$. The dilution study with La substituted on the Ce site will be also presented to further discuss the Kondo effect in this system.