Work

Electron correlation effect in the thermoelectric oxide Ca 3− x Sr x Co 4 O 9 single crystals

Year: 2017

Type: article

Abstract: We have measured the transport properties of the thermoelectric layered oxide Ca 3− x Sr x Co 4 O 9 ( ) single crystals to examine the electron correlation effect. Both the electrical resistivity and the Seebeck coefficient systematically vary with increasing Sr content x . In all the present crystals, the resistivity shows a Fermi-liquid behavior of ρ = ρ 0 + AT 2 at around 120 K, and A increases with increasing Sr content, indicating that the effective mass is enhanced by the substitution. It is also found that the low-temperature Seebeck coefficient increases with increasing Sr content. These results suggest that the present isovalent Sr substitution acts as a negative pressure on this compound and that the two dimensionality is thus enhanced by the substitution, leading to a strong renormalization of the effective mass. We also discuss the Sr-substitution effect on the carrier concentration.

Source: Japanese Journal of Applied Physics

DOI: 10.7567/jjap.56.043201

Authors: Kengo Saito, Ryuji Okazaki

Institution: Tokyo University of Science

Language: English

Topic: Advanced Thermoelectric Materials and Devices

Subfield: Materials Chemistry

Field: Materials Science

Domain: Physical Sciences

Open Access status: bronze

Funder: Japan Society for the Promotion of Science

Award: Thermal switching effect by electrical currents