|An EXAFS Analysis of the Thermoelectric Skutterudite SmOs4Sb12 Crystal|
|Presenter||Nathan Daniel Martinez|
|Full Author List||N. D. Martinez , T. Keiber , F. Bridges|
University of California, Santa Cruz
Skutterudites are excellent thermoelectric materials with applications such as waste heat reclamation, where a temperature gradient is used to generate electrical current. The SmOs4Sb12 skutterudite has unusual properties that are speculated to arise from the large amplitude vibrations of the Sm “Rattler” atom in the surrounding "cage" of atoms. We used the Extended X-ray Absorption Fine Structure (EXAFS) technique to analyze the local structure about the Sm atom; this technique requires high intensity flux, available at Stanford Synchrotron Radiation Lightsource (SSRL). For the Sm data, the Sm-Sb and Sm-Os pairs both contribute to the EXAFS peak near 3.5 A. and the fit must include both pairs. The temperature dependence of σ2 for each atom pair was determined as a function of temperature from 8-190 K and fit to an Einstein model.