Nanoscale clusters in the high performance thermoelectric AgPbmSbTem+2
  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. 
H. Lin, E. S. Bozin, S. J. L. Billinge, E. Quarez, M. G. Kanatzidis