Session P29: Focus Session: Thermoelectrics III: IV-VI's & Nanostructures
8:00 AM–10:48 AM, Wednesday, March 17, 2010
Room: C123
Sponsoring Units:
DMP FIAP GERA
Chair: Chris Dames, University of California, Riverside
Abstract ID: BAPS.2010.MAR.P29.6
Abstract: P29.00006 : Investigating the coherent phase stability of the PbS-PbTe system using first principles calculations
9:24 AM–9:36 AM
Preview Abstract
MathJax On | Off 
Abstract 
Authors:
William Counts
(Northwestern University)
Chris Wolverton
(Northwestern University)
Nanoscale inhomogeneities in PbS-PbTe alloys may enhance thermoelectric properties of these materials. The phase diagram and coherent spinodal are key factors controlling these nanostructured morphologies. We study the coherent phase stability of PbS-PbTe using density functional theory based calculations, a mixed-space cluster expansion, and Monte Carlo simulations. (i) Our calculations correctly reproduce the phase separating tendency of the PbS-PbTe phase diagram. (ii) Strain energy calculations show that for this rocksalt-based system (100) is the elastically hardest direction and that (111) is the softest. (iii) The formation energies for the PbS-PbTe structures are of the same order as the strain energies suggesting that strain energy will significantly depress spinodal decomposition in this system.
To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2010.MAR.P29.6