Jump to main content
Jump to site search
PLANNED MAINTENANCE Close the message box

Scheduled maintenance upgrade on Thursday 4th of May 2017 from 8.00am to 9.00am (BST).

During this time our websites will be offline temporarily. If you have any questions please use the feedback button on this page. We apologise for any inconvenience this might cause and thank you for your patience.


Issue 28, 2013
Previous Article Next Article

A comprehensive study of the crystallization of Cu–As–Te glasses: microstructure and thermoelectric properties

Author affiliations

Abstract

We report a thorough experimental study on the microstructure, thermal behavior and thermoelectric properties of the amorphous composition Cu15As30Te55 and the glass–ceramics related-compounds synthesized by using the Spark Plasma Sintering (SPS) technique. Varying the conditions of the SPS process enables the synthesis of composite glassy-crystalline samples with different crystal/glass ratios. Such treatments result in complex microstructures composed of large glassy domains where nanocrystals of the metastable β-As2Te3 phase are embedded. These domains are separated by regions of the dendritic crystalline phase surrounded by a Cu-rich glassy matrix. The presence of β-As2Te3, confirmed by both powder X-ray diffraction and scanning electron microscopy, suggests that pressure and/or internal stresses play an important role in stabilizing this phase. This conclusion is further supported by neutron thermodiffraction experiments revealing a sharp crossover from the β-As2Te3 to the stable α-As2Te3 phase at temperatures below that of the SPS treatment. Transport properties measurements show that the presence of a crystalline fraction significantly lowers the electrical resistivity by four orders of magnitude. However, the probable intrinsic n-type behavior of β-As2Te3 has a detrimental influence on the thermopower values. Even though the partial crystallization of the glassy matrix leads to an increase in the thermal conductivity, the measured values remain on the order of 1 W m−1 K−1 at 300 K. Besides an overall increase in the dimensionless figure of merit ZT, our results demonstrate that the partial crystallization of an amorphous matrix is an efficient tool to tune the electrical resistivity over several orders of magnitude while maintaining low thermal conductivity values.

Graphical abstract: A comprehensive study of the crystallization of Cu–As–Te glasses: microstructure and thermoelectric properties

Back to tab navigation
Please wait while Download options loads

Publication details

The article was received on 21 Mar 2013, accepted on 10 May 2013 and first published on 13 May 2013


Article type: Paper
DOI: 10.1039/C3TA11159H
Citation: J. Mater. Chem. A, 2013,1, 8190-8200
  •   Request permissions

    A comprehensive study of the crystallization of Cu–As–Te glasses: microstructure and thermoelectric properties

    J. B. Vaney, G. Delaizir, E. Alleno, O. Rouleau, A. Piarristeguy, J. Monnier, C. Godart, M. Ribes, R. Escalier, A. Pradel, A. P. Gonçalves, E. B. Lopes, G. J. Cuello, P. Ziolkowski, E. Müller, C. Candolfi, A. Dauscher and B. Lenoir, J. Mater. Chem. A, 2013, 1, 8190
    DOI: 10.1039/C3TA11159H

Search articles by author