Thermoelectric properties of a Mn substituted synthetic tetrahedrite
- Author(s)
- Raju Chetty, Prem D. S. Kumar, Gerda Rogl, Peter Rogl, Ernst Bauer, Herwig Michor, Satyam Suwas, Stephan Puchegger, Gerald Giester, Ramesh Chandra Mallik
- Abstract
Tetrahedrite compds. Cu12-xMnxSb4S13 (0 = x = 1.8) were prepd. by solid state synthesis. A detailed crystal structure anal. of Cu10.6Mn1.4Sb4S13 was performed by single crystal X-ray diffraction (XRD) at 100, 200 and 300 K confirming the noncentrosym. structure (space group I4[n.773]3m) of a tetrahedrite. The large at. displacement parameter of the Cu2 atoms was described by splitting the 12e site into a partially and randomly occupied 24g site (Cu22) in addn. to the regular 12e site (Cu21), suggesting a mix of dynamic and static off-plane Cu2 atom disorder. Rietveld powder XRD pattern and electron probe microanal. revealed that all the Mn substituted samples showed a single tetrahedrite phase. The elec. resistivity increased with increasing Mn due to substitution of Mn2+ at the Cu1+ site. The pos. Seebeck coeff. for all samples indicates that the dominant carriers are holes. Even though the thermal cond. decreased as a function of increasing Mn, the thermoelec. figure of merit ZT decreased, because the decrease of the power factor is stronger than the decrease of the thermal cond. The max. ZT = 0.76 at 623 K is obtained for Cu12Sb4S13. The coeff. of thermal expansion 13.5 ± 0.1 × 10-6 K-1 is obtained in the temp. range from 460 K to 670 K for Cu10.2Mn1.8Sb4S13. The Debye temp., TD = 244 K for Cu10.2Mn1.8Sb4S13, was estd. from an evaluation of the elastic properties. The effective paramagnetic moment 7.45 µB/f.u. for Cu10.2Mn1.8Sb4S13 is fairly consistent with a high spin 3d5 ground state of Mn.
- Organisation(s)
- Department of Physical Chemistry, Faculty Center for Nano Structure Research, Department of Mineralogy and Crystallography
- External organisation(s)
- Indian Institute of Science, Technische Universität Wien
- Journal
- Physical Chemistry Chemical Physics
- Volume
- 17
- Pages
- 1716-1727
- No. of pages
- 12
- ISSN
- 1463-9076
- DOI
- https://doi.org/10.1039/c4cp04039b
- Publication date
- 01-2015
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 104017 Physical chemistry, 104011 Materials chemistry, 105113 Crystallography
- Keywords
- ASJC Scopus subject areas
- General Physics and Astronomy, Physical and Theoretical Chemistry
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/41ddc264-cb43-44fd-92bf-87cf901d2ed7