Michigan State University, USA
Posters & Accepted Abstracts: Res. Rev. J Mat. Sci
Tetrahedrites with the general compostion of Cu12-xMxSb4S13 recently have emerged as promising thermoelectrics with earthabundant and environment-friendly elements. While it has been shown that they possess favorable electronic properties and low lattice thermal conductivity (<1 W m-1 K-1 for a wide temperature range), the vibrational dynamics in this family of materials is not well-understood. In this talk, we will present some of our integrated computational and experimental efforts to study anomalous vibrational dynamics in tetrahedrites. We will first show computational results on the electron density, heat capacity, elastic moduli, and EXAFS spectra that agree with experiments. We will then focus on the role of lone-pair electrons of Sb on the vibrational dynamics, anomalous “phonon softening upon cooling”, and quasi-localized vibration modes that lead to low lattice thermal conductivity.