Hostname: page-component-586b7cd67f-t7fkt Total loading time: 0 Render date: 2024-11-28T04:40:41.395Z Has data issue: false hasContentIssue false

Large thermoelectric power generated by the van Hove singularity in NaxCoO2

Published online by Cambridge University Press:  01 February 2011

Tsunehiro Takeuchi
Affiliation:
[email protected], Nagoya University, EcoTopia Science Institute, Furo-cho, Chikusa-ku, Nagoya, 464-8603, Japan, +81-52-789-4461, +81-52-789-4461
Syuhei Kuno
Affiliation:
[email protected], Nagoya University, Department of Crystalline Materials Science, Nagoya, 464-8603, Japan
Get access

Abstract

Mechanism leading to the large thermoelectric power and metallic electrical conduction observed in NaxCoO2 was investigated by means of angle resolved photoemission spectroscopy and the Bloch-Boltzmann theory. As a result of thermoelectric power calculation using the experimentally determined electronic structure under the assumptions of rigid band and constant mean free path, NaxCoO2 were found to possess the Boltzmann-type electrical conduction over a wide carrier-concentration range. Analysis using the simplest tight-binding bands revealed that the two-dimensional hexagonal lattices including the crystalline structure of the present NaxCoO2 produce a characteristic spectral conductivity leading to the large thermoelectric power and metallic electrical conduction.

Type
Research Article
Copyright
Copyright © Materials Research Society 2008

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1. Terasaki, I., Sasago, Y., and Uchinokura, K.: Phys. Rev. B 56 (1997) R12685–R12687.Google Scholar
2. Valla, T. et al. , Nature 417 (2002) 627630.Google Scholar
3. Funahashi, R. et al. , Jpn. J. Appl. Phys. 39 (2000) L1127–L1129.Google Scholar
4.For example, Singh, D. J., Phys. Rev. B 61 (2000) 1339713402.Google Scholar
5. Takeuchi, T. et al. , Phy. Rev. B 69 (2004) 125410.Google Scholar
6. Koshibae, W., Tsutsui, K., and Maekawa, S., Phys. Rev. B 62 (2000) 68696872. W. Koshibae, and S. Maekawa, Phys. Rev. Lett. 87 (2001) 236603.Google Scholar
7. Kitao, T. et al. , Trans. MRSJ 31 (2006) 367370. T. Takeuchi et al., Proc. of ICT 2005 (Clemson University, USA, 20 June - 25 June, 2005). S. Kuno et al., Proc. of ICT 2007 (2007/6/3-6/7, Jeju, South Korea).Google Scholar
8. Mikami, M. et al. , Jpn. J. Appl. Phys. 42 (2003) 73837386.Google Scholar
9. Foo, M. L. et al. , Phys. Rev. Lett. 92 (2004) 247001.Google Scholar
10. Kondo, T. et al. , Phys. Rev. B 72 (2005) 024533.Google Scholar
11. Takeuchi, T. et al. , Phys. Rev. B 74 (2006) 054206.Google Scholar