Network theory for inhomogeneous thermoelectrics. (4th April 2016)

• Record Type: Journal Article
• Authors: Angst, Sebastian; Wolf, Dietrich E
• Is Part Of: New journal of physics. Volume 18:Number 4(2016:Apr.)
• Publication Date: 2016-04-04
• Subjects: thermoelectrics -- inhomogeneous material -- Harman method -- network model; 7425fg -- 7363-b -- 4410 + i; Physics -- Periodicals; Physics; Periodicals; 530.05
• DOI: 10.1088/1367-2630/18/4/043004
• Languages: English
• ISSNs: 1367-2630

Abstract

Abstract: The Onsager–de Groot–Callen transport theory, implemented as a network model, is used to simulate the transient Harman method, which is widely used experimentally to determine all thermoelectric transport coefficients in a single measurement setup. It is shown that this method systematically overestimates the Seebeck coefficient for samples composed of two different materials. As a consequence, the figure of merit is also overestimated, if the thermal coupling of the measurement setup to the environment is weak. For a mixture of metal and semiconductor particles near metal percolation the figure of merit obtained by the Harman method is more than 100% too large. For a correct interpretation of the experimental data, information on composition and microstructure of the sample are indispensable.