Work

Enhancement of the effective disorder potential and thermopower in Na x CoO 2 through electron-phonon coupling

Year: 2012

Type: article

Abstract: The effects of an electron-phonon ($e$-ph) interaction on the thermoelectric properties of Na${}_{x}$CoO${}_{2}$ are analyzed. By means of dynamical mean-field theory calculations we find that the $e$-ph coupling acts in a cooperative way with the disorder, enhancing the effective binary disorder potential strength on the Co sites, which stems from the presence or absence of a neighboring Na atom. Hence, the inclusion of the $e$-ph coupling allows us to assume smaller values of the binary disorder potential strength---which for Na${}_{x}$CoO${}_{2}$ are in fact also more reasonable. More generally, we can conclude that the interplay between disorder effects and coupling to the lattice can be exploited to engineer more efficient thermoelectric materials.

Source: Physical Review B

DOI: 10.1103/physrevb.86.035123

Authors: G. Sangiovanni, P. Wissgott, F. Assaad, A. Toschi, K. Held

Institutions: TU Wien, University of Würzburg

Language: English

Topic: Advanced Thermoelectric Materials and Devices

Subfield: Materials Chemistry

Field: Materials Science

Domain: Physical Sciences

Open Access status: green

Funders: Deutsche Forschungsgemeinschaft, Austrian Science Fund

Awards: G2025742893, At the frontiers of phonons and correlated electrons, G5295212483