Inelastic neutron scattering study on the phonon DOS of Zintl AB2X2

The application of thermoelectric (TE) materials can improving the energy utility efficiency. For looking for the high-performance TE material, a straightforward way is to decrease the lattice thermal conductivity. AB2X2-type Zintl compounds (EuZn2Sb2, CaZn2Sb2, YbZn2Sb2, YbCd2Sb2, etc.) have been the widely investigated. we found a promising new thermoelectric material Eu2ZnSb2 with intrinsically ultralow lattice thermal conductivity, By comparing the lattice thermal conductivity of some relevant Zintl phases. we proposed that crystal structure and the incomplete site occupancy of Zn might be the reason of the ultralow lattice thermal conductivity. However, detailed analysis on the crystal structure and dynamic structure have not been done, which is important for the understanding of phonon scattering process and the ultralow lattice thermal conductivity.