Finding new thermoelectric compounds using crystallographic data: atomic displacement parameters

A new structure-property relationship is discussed which links atomic displacement parameters (ADPs) and the lattice thermal conductivity of clathrate-like compounds. For many clathrate-like compounds, in which one of the atom types is weakly bound and "rattles" within its atomic cage, room temperature ADP information can be used to estimate the room temperature lattice thermal conductivity, the vibration frequency of the "rattler", and the temperature dependence of the heat capacity. Neutron data and X-ray crystallography data, reported in the literature, are used to apply this analysis to several promising classes of thermoelectric materials.