ePrints@IIScePrints@IISc Home | About | Browse | Latest Additions | Advanced Search | Contact | Help

Thermoelectric properties of PbTe with encapsulated bismuth secondary phase

Bali, Ashoka and Royanian, Esmaeil and Bauer, Ernst and Rogl, Peter and Mallik, Ramesh Chandra (2013) Thermoelectric properties of PbTe with encapsulated bismuth secondary phase. In: JOURNAL OF APPLIED PHYSICS, 113 (12).

[img] PDF
jl_app_phy_113_12_123707_2013.pdf - Published Version
Restricted to Registered users only

Download (2MB) | Request a copy
Official URL: http://dx.doi.org/10.1063/1.4796148


Lead Telluride (PbTe) with bismuth secondary phase embedded in the bulk has been prepared by matrix encapsulation technique. X-Ray Diffraction results indicated crystalline PbTe, while Rietveld analysis showed that Bi did not substitute at either Pb or Te site, which was further confirmed by Raman and X-Ray Photoelectron Spectroscopy. Scanning Electron Microscopy showed the expected presence of a secondary phase, while Energy Dispersive Spectroscopy results showed a slight deficiency of tellurium in the PbTe matrix, which might have occurred during synthesis due to higher vapor pressure of Te. Transmission Electron Microscopy results did not show any nanometer sized Bi phase. Seebeck coefficient (S) and electrical conductivity (sigma) were measured from room temperature to 725 K. A decrease in S and sigma with increasing Bi content showed an increased scattering of electrons from PbTe-Bi interfaces, along with a possible electron acceptor role of Bi secondary phase. An overall decrease in the power factor was thus observed. Thermal conductivity, measured from 400K to 725K, was smaller at starting temperature with increasing Bi concentration, and almost comparable to that of PbTe at higher temperatures, indicating a more important role of electrons as compared to phonons at PbTe-Bi interfaces. Still, a reasonable zT of 0.8 at 725K was achieved for undoped PbTe, but no improvement was found for bismuth added samples with micrometer inclusions. (C) 2013 American Institute of Physics. http://dx.doi.org/10.1063/1.4796148]

Item Type: Journal Article
Additional Information: Copyright for this article belongs to the AMER INST PHYSICS, USA.
Department/Centre: Division of Physical & Mathematical Sciences > Physics
Date Deposited: 14 May 2013 07:26
Last Modified: 14 May 2013 07:26
URI: http://eprints.iisc.ac.in/id/eprint/46493

Actions (login required)

View Item View Item