| About this Abstract |
| Meeting |
2010 TMS Annual Meeting & Exhibition
|
| Symposium
|
Solid-State Interfaces: Toward an Atomistic-Scale Understanding of Structure, Properties, and Behavior through Theory and Experiment
|
| Presentation Title |
Interfacial Defect Mechanism in the Precipitation of Tetradymite Plates in Rocksalt-Structured Tellurides |
| Author(s) |
Douglas L. Medlin, J. D. Sugar |
| On-Site Speaker (Planned) |
Douglas L. Medlin |
| Abstract Scope |
Controlling the formation and stability of interfaces is important in developing high performance thermoelectric nanocomposites. Here, we consider the transformation mechanism between rocksalt and tetradymite-structured tellurides. Such compounds encompass a wide range of important thermoelectric materials. Our HRTEM observations of tetradymite-structured Sb<SUB>2</SUB>Te<SUB>3</SUB> plates within rocksalt structured AgSbTe<SUB>2</SUB> have identified a defect that can transform the rocksalt phase to the tetradymite phase through a diffusive-glide mechanism. We analyze this mechanism by establishing the geometric properties of the defect-- namely its step height and Burgers vector, which has components both perpendicular and parallel to the interface. Climb of the perpendicular dislocation component removes a metal plane from the rocksalt phase, forming the tellurium double-layer. Glide of the parallel component places the close-packed planes into the correct tetradymite stacking sequence. The defect properties also give the atomic flux requirements for defect motion, which we analyze for different compositions of the two phases. |
| Proceedings Inclusion? |
Definite: A CD-only volume |