  The local structure of the AgPbmSbTem+2 series of thermoelectric materials
has been studied using the atomic pair distribution function (PDF) method.
Three candidate-models were attempted for the structure of this class of
materials using either a one-phase or a two-phase modeling procedure. Combining
modeling the PDF with HRTEM data we show that AgPbmSbTem+2 contains nanoscale
inclusions with composition close to AgPb3SbTe5 randomly embedded in a PbTe
matrix.
