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Influence of power factor enhancement on the thermoelectric figure of merit in Mg 2 Si 0.4 Sn 0.6 based materials
Author(s) -
Dasgupta T.,
Stiewe C.,
de Boor J.,
Müller E.
Publication year - 2014
Publication title -
physica status solidi (a)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.532
H-Index - 104
eISSN - 1862-6319
pISSN - 1862-6300
DOI - 10.1002/pssa.201300196
Subject(s) - materials science , figure of merit , doping , thermoelectric effect , analytical chemistry (journal) , seebeck coefficient , electron mobility , effective mass (spring–mass system) , hall effect , electrical resistivity and conductivity , thermal conductivity , chemistry , optoelectronics , thermodynamics , composite material , physics , chromatography , quantum mechanics
The influence of power factor enhancement on the superior thermoelectric (TE) performance of Mg 2 (Si,Sn) is studied based on a comparison with Mg 2 Si. Doped compounds with compositions of Mg 2 (Si 0.4 Sn 0.6 ) are synthesized and the TE properties measured between room temperature and 773 K. Carrier concentration and hall mobilities at room temperature are measured on selected samples. Enhancement of the density‐of‐states effective mass and mobilities comparable to Mg 2 Si indicate band convergence in the solid solutions to be the cause of the power factor enhancement. Microstructural analysis shows the presence of secondary Si rich phases while the matrix corresponds to Mg 2 (Si 0.3 Sn 0.7 ). A doped compound with this composition is synthesized and exhibits superior ZT values (compared to the Mg 2 (Si 0.4 Sn 0.6 ) specimens) with a ZT max ∼1.3 at 773 K.