Dopant Distributions in PbTe-Based Thermoelectric Materials
نویسندگان
چکیده
Atom-probe tomography (APT) is utilized to characterize the dopant distribution in two thermoelectric materials systems: (1) PbTe-2 mol.%SrTe1 mol.%Na2Te, and (2) codoped PbTe-1.25 mol.%K-1.4 mol.%Na. We observe the presence of Na-rich precipitates of a few nanometers in diameter in both systems. Both concentration frequency distribution analyses and partial radial distribution functions are employed to analyze the tendency for dopant clustering detected by APT. In the codoped sample, K accumulates significantly in Na-rich precipitates, while in the Sr-containing sample, Sr is homogeneously distributed. High-resolution transmission electron microscopy also reveals the presence of precipitates having platelet morphology, which are oriented parallel to the {001} planes.
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