A document presents a study of why materials of composition (Ag1–ySbTe2)0.05 (PbTe)0.95 [0≤y≤1] were previously reported to have values of the thermoelectric figure of merit [ZT (where Z =α2/ρκ, α is the Seebeck coefficient, ρ is electrical resistivity, κ is thermal conductivity, and T is absolute temperature)] ranging from 2. In the study, samples of (AgSbTe2)0.05(PbTe)0.95, (Ag0.67SbTe2)0.05 (PbTe)0.95, and (Ag0.55SbTe2)0.05(PbTe)0.95 were prepared by melting followed, variously, by slow or rapid cooling. Analyses of these samples by x-ray diffraction, electron microscopy, and scanning microprobe measurements of the Seebeck coefficient led to the conclusion that these materials have a multiphase character on a scale of the order of millimeters, even though they appear homogeneous in x-ray diffraction and electron microscopy. The Seebeck measurements showed significant variations, including both n-type and p-type behavior in the same sample. These variations were found to be consistent with observed variations of ZT. The rapidly quenched samples were found to be less inhomogeneous than were the furnace-cooled ones; hence, rapid quenching was suggested as a basis of research on synthesizing more nearly uniform high-ZT samples.
This work was done by G. Jeffrey Snyder, Nancy Chen, Franck Gascoin, Eckhard Mueller, Gabriele Karpinski, and Christian Stiewe of Caltech for NASA’s Jet Propulsion Laboratory. For further information, access the Technical Support Package (TSP) free online at www.techbriefs.com /tsp under the Materials category. NPO-42657
This Brief includes a Technical Support Package (TSP).
Thermoelectric Inhomogeneities (Ag1-YSbTe2)X(PbTe)1-X
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Overview
The document is a Technical Support Package from NASA's Jet Propulsion Laboratory (JPL) focused on thermoelectric inhomogeneities in the material system (Ag1–ySbTe2)x(PbTe)1–x. This research is part of NASA's Commercial Technology Program, which aims to disseminate aerospace-related developments with broader technological, scientific, or commercial applications.
The primary focus of the document is on the macroscopic thermoelectric inhomogeneities observed in the specified material system. The research is conducted by a team of scientists from JPL and the German Aerospace Center (DLR), highlighting international collaboration in advancing materials science. The findings were presented at the ICT Thermoelectrics Conference held in Clemson, South Carolina, on June 21, 2005, and were published in the journal "Applied Physics Letters" on October 24, 2005.
Thermoelectric materials are crucial for converting temperature differences into electrical voltage and vice versa, making them valuable for power generation and refrigeration applications. The specific material system discussed, (Ag1–ySbTe2)x(PbTe)1–x, is of interest due to its potential to enhance thermoelectric efficiency, which is essential for various applications, including space exploration and energy harvesting.
The document emphasizes the importance of understanding the inhomogeneities within these materials, as they can significantly affect the thermoelectric performance. The research aims to provide insights into the microstructural characteristics and how they influence the overall thermoelectric properties, which could lead to the development of more efficient materials.
Additionally, the document includes contact information for further inquiries and access to additional resources through the NASA Scientific and Technical Information (STI) Program Office. It also contains a disclaimer regarding the use of the information provided, clarifying that the U.S. Government does not assume liability for its application.
In summary, this Technical Support Package serves as a valuable resource for researchers and industry professionals interested in thermoelectric materials, offering insights into the latest findings and potential applications in aerospace and other fields. The collaboration between JPL and DLR underscores the global effort to advance materials science and technology for future innovations.
