Substitution in MxZn4-xSb3: Effect on Thermal Stability, Crystal Structure, Phase Transitions, and Thermoelectric Performance
2010 (English)In: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, Vol. 22, no 7, 2375-2383 p.Article in journal (Refereed) Published
The effects of Cd substitution in MxZn4-xSb3 on the high-temperature thermal stability, low-temperature phase transitions and thermoelectric properties have been studied on three samples with a substitution degree of 0.1, 1, and 2 at % Cd (x = 0.004, 0.04, 0.08). The high-temperature thermal stability in atmospheric air of a I % substituted sample is compared with an unsubstituted Zn4Sb3 sample. Multitemperature synchrotron powder diffraction data reveals that while only similar to 42 wt % of the original Zn4Sb3 phase remains in the unsubstituted sample after three heating cycles to 625 K, 78 wt % is preserved in the Cd-substituted sample. Thus, Cd-substitution provides a significant improvement of the thermal stability of Zn4Sb3. Multitemperature synchrotron powder diffraction data measured between 90 and 300 K reveal that Cd substitution has a suppressing effect on the alpha'-alpha-beta phase transitions. With increasing substitution, there is also a significant change in the individual Zn site occupancies. Differential scanning calorimetry shows an apparent correlation between Cd content and phase transition temperature. Thermoelectric properties have been measured from 2 to 400 K for all samples, and although some physical properties are significantly affected by doping, no immediate improvement of ZT was achieved.
Place, publisher, year, edition, pages
2010. Vol. 22, no 7, 2375-2383 p.
LOW-TEMPERATURES; PHONON-GLASS; BETA-ZN4SB3; ZN4SB3; SYSTEM; ZINC
Research subject Materials Chemistry
IdentifiersURN: urn:nbn:se:su:diva-50137DOI: 10.1021/m903659gISI: 000276394800027OAI: oai:DiVA.org:su-50137DiVA: diva2:380575
authorCount :52010-12-212010-12-212010-12-21Bibliographically approved