Publikationen

Thermoelectric properties of a Mn substituted synthetic tetrahedrite

Autor(en)
Raju Chetty, Prem D. S. Kumar, Gerda Rogl, Peter Rogl, Ernst Bauer, Herwig Michor, Satyam Suwas, Stephan Puchegger, Gerald Giester, Ramesh Chandra Mallik
Abstrakt

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(en)
Institut für Physikalische Chemie, Fakultätszentrum für Nanostrukturforschung, Institut für Mineralogie und Kristallographie
Externe Organisation(en)
Indian Institute of Science, Technische Universität Wien
Journal
Physical Chemistry Chemical Physics - PCCP
Band
17
Seiten
1716-1727
Anzahl der Seiten
12
ISSN
1463-9076
DOI
https://doi.org/10.1039/c4cp04039b
Publikationsdatum
01-2015
Peer-reviewed
Ja
ÖFOS 2012
Physikalische Chemie, Materialchemie, Kristallographie
Schlagwörter
Link zum Portal
https://ucris.univie.ac.at/portal/de/publications/thermoelectric-properties-of-a-mn-substituted-synthetic-tetrahedrite(41ddc264-cb43-44fd-92bf-87cf901d2ed7).html