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

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

104017 Physikalische Chemie, 104011 Materialchemie, 105113 Kristallographie

Schlagwörter

ASJC Scopus Sachgebiete

Physics and Astronomy(all), Physical and Theoretical Chemistry

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