Nonlinear thermoelectric properties of layered cobalt oxides

Tomohito Nakano; Wataru Kobayashi; Ryoji Funahashi; Kenji Sugiura; Hiromichi Ohta; Kunihito Koumoto; Ichiro Terasaki

doi:10.1109/ICT.2007.4569438

Nonlinear thermoelectric properties of layered cobalt oxides

Tomohito Nakano^*, Wataru Kobayashi, Ryoji Funahashi, Kenji Sugiura, Hiromichi Ohta, Kunihito Koumoto, Ichiro Terasaki

^*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceeding › Conference contribution

Abstract

We synthesized whisker-crystal and thin-film samples of the layered cobalt oxide (Bi₂Sr₂O₄)_xCoO₂ well known as a candidate of a thermoelectric material, and measured their resistivity, voltage-current characteristics and magnetoresistance with pulsed currents. Resistivity of the whisker sample with a small current density of 2 mA/cm₂ increases with decreasing temperature below 100 K, suggesting development of a pseudogap on the density of states. This increase is suppressed by a large current density of 110 A/cm². The nonlinear voltage-current characteristics are observed both for the whisker and thin-film samples. The negative magnetoresistance of the thin-film sample is suppressed by current density. These suggest that the density of states recovers owing to the suppression of the pseudogap by applying large current density.

Original language	English
Title of host publication	Proceedings ICT'07 - 26th International Conference on Thermoelectrics
Pages	121-123
Number of pages	3
DOIs	https://doi.org/10.1109/ICT.2007.4569438
Publication status	Published - 2007
Event	ICT'07 - 26th International Conference on Thermoelectrics - Jeju, Korea, Republic of Duration: 2007 Jun 3 → 2007 Jun 7

Other

Other	ICT'07 - 26th International Conference on Thermoelectrics
Country/Territory	Korea, Republic of
City	Jeju
Period	07/6/3 → 07/6/7

ASJC Scopus subject areas

Engineering(all)

Access to Document

10.1109/ICT.2007.4569438

Cite this

Nakano, T, Kobayashi, W, Funahashi, R, Sugiura, K, Ohta, H, Koumoto, K & Terasaki, I 2007, Nonlinear thermoelectric properties of layered cobalt oxides. in Proceedings ICT'07 - 26th International Conference on Thermoelectrics., 4569438, pp. 121-123, ICT'07 - 26th International Conference on Thermoelectrics, Jeju, Korea, Republic of, 07/6/3. https://doi.org/10.1109/ICT.2007.4569438

@inproceedings{a33a557db7f3444da379d993f6b3a5f5,

title = "Nonlinear thermoelectric properties of layered cobalt oxides",

abstract = "We synthesized whisker-crystal and thin-film samples of the layered cobalt oxide (Bi2Sr2O4)xCoO2 well known as a candidate of a thermoelectric material, and measured their resistivity, voltage-current characteristics and magnetoresistance with pulsed currents. Resistivity of the whisker sample with a small current density of 2 mA/cm2 increases with decreasing temperature below 100 K, suggesting development of a pseudogap on the density of states. This increase is suppressed by a large current density of 110 A/cm2. The nonlinear voltage-current characteristics are observed both for the whisker and thin-film samples. The negative magnetoresistance of the thin-film sample is suppressed by current density. These suggest that the density of states recovers owing to the suppression of the pseudogap by applying large current density.",

author = "Tomohito Nakano and Wataru Kobayashi and Ryoji Funahashi and Kenji Sugiura and Hiromichi Ohta and Kunihito Koumoto and Ichiro Terasaki",

year = "2007",

doi = "10.1109/ICT.2007.4569438",

language = "English",

isbn = "9781424422623",

pages = "121--123",

booktitle = "Proceedings ICT'07 - 26th International Conference on Thermoelectrics",

note = "ICT'07 - 26th International Conference on Thermoelectrics ; Conference date: 03-06-2007 Through 07-06-2007",

}

TY - GEN

T1 - Nonlinear thermoelectric properties of layered cobalt oxides

AU - Nakano, Tomohito

AU - Kobayashi, Wataru

AU - Funahashi, Ryoji

AU - Sugiura, Kenji

AU - Ohta, Hiromichi

AU - Koumoto, Kunihito

AU - Terasaki, Ichiro

PY - 2007

Y1 - 2007

N2 - We synthesized whisker-crystal and thin-film samples of the layered cobalt oxide (Bi2Sr2O4)xCoO2 well known as a candidate of a thermoelectric material, and measured their resistivity, voltage-current characteristics and magnetoresistance with pulsed currents. Resistivity of the whisker sample with a small current density of 2 mA/cm2 increases with decreasing temperature below 100 K, suggesting development of a pseudogap on the density of states. This increase is suppressed by a large current density of 110 A/cm2. The nonlinear voltage-current characteristics are observed both for the whisker and thin-film samples. The negative magnetoresistance of the thin-film sample is suppressed by current density. These suggest that the density of states recovers owing to the suppression of the pseudogap by applying large current density.

AB - We synthesized whisker-crystal and thin-film samples of the layered cobalt oxide (Bi2Sr2O4)xCoO2 well known as a candidate of a thermoelectric material, and measured their resistivity, voltage-current characteristics and magnetoresistance with pulsed currents. Resistivity of the whisker sample with a small current density of 2 mA/cm2 increases with decreasing temperature below 100 K, suggesting development of a pseudogap on the density of states. This increase is suppressed by a large current density of 110 A/cm2. The nonlinear voltage-current characteristics are observed both for the whisker and thin-film samples. The negative magnetoresistance of the thin-film sample is suppressed by current density. These suggest that the density of states recovers owing to the suppression of the pseudogap by applying large current density.

UR - http://www.scopus.com/inward/record.url?scp=51849105652&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=51849105652&partnerID=8YFLogxK

U2 - 10.1109/ICT.2007.4569438

DO - 10.1109/ICT.2007.4569438

M3 - Conference contribution

AN - SCOPUS:51849105652

SN - 9781424422623

SP - 121

EP - 123

BT - Proceedings ICT'07 - 26th International Conference on Thermoelectrics

T2 - ICT'07 - 26th International Conference on Thermoelectrics

Y2 - 3 June 2007 through 7 June 2007

ER -

Nonlinear thermoelectric properties of layered cobalt oxides

Abstract

Other

ASJC Scopus subject areas

Access to Document

Other files and links

Fingerprint

Cite this