Hostname: page-component-78c5997874-lj6df Total loading time: 0 Render date: 2024-11-20T05:28:41.119Z Has data issue: false hasContentIssue false

Thermoelectric Properties and Magnetic Anisotropies of Magnetically Grain-Oriented Sr- or Bi-doped Ca3Co4O9 Thick Films

Published online by Cambridge University Press:  01 February 2011

Shigeru Horii
Affiliation:
[email protected], The University of Tokyo, Dept. Appl. Chem., Hongo 7-3-1, Bunkyo-ku, Tokyo, 113-8656, Japan
Yuhya Yamasaki
Affiliation:
[email protected], The University of Tokyo, Department of Applied Chemistry, Tokyo, 113-8656, Japan
Masayuki Sakurai
Affiliation:
[email protected], The University of Tokyo, Department of Applied Chemistry, Tokyo, 113-8656, Japan
Ryoji Funahashi
Affiliation:
[email protected], National Institute of Advanced Industrial Science and Technology, Ikeda, 563-8577, Japan
Tetsuo Uchikoshi
Affiliation:
[email protected], National Institute for Materials Science, Tsukuba, 305-0047, Japan
Tohru S Suzuki
Affiliation:
[email protected], National Institute for Materials Science, Tsukuba, 305-0047, Japan
Yoshio Sakka
Affiliation:
[email protected], National Institute for Materials Science, Tsukuba, 305-0047, Japan
Hiraku Ogino
Affiliation:
[email protected], The University of Tokyo, Department of Applied Chemistry, Tokyo, 113-8656, Japan
Jun-ichi Shimoyama
Affiliation:
[email protected], The University of Tokyo, Department of Applied Chemistry, Tokyo, 113-8656, Japan
Kohji Kishio
Affiliation:
[email protected], The University of Tokyo, Department of Applied Chemistry, Tokyo, 113-8656, Japan
Get access

Abstract

We report magnetic properties of [Ca2CoO3-δ]0.62CoO2 (Ca349) powders with various average size and the Bi- and Sr-doping effects on thermoelectric properties for the magnetically grain-aligned and densified Ca349 thick films. Magnetic anisotropy at 300 K depended on the initial average size of Ca349 powders and decreased with the decrease in the size. This presumably suggests that distortion of crystal structure was induced by a ball-milling process and led to the change of magnetic anisotropy. On the Bi- and Sr-doping effects, an obvious enhancement of thermoelectric properties did not emerge in the case of the Sr-doping, whereas the enhancement was observed for the Bi-doped Ca349 thick films. However, a drastic decrease of magnetic anisotropy was caused by the Bi-doping. For usage of the p-type layer in multilayered thermoelectric module, tuning of the Bi-doping levels in which both enhancement of thermoelectric properties and a certain level of magnetic anisotropy are achieved is required.

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.Google Scholar
2. Miyazaki, Y., Kudo, K., Akoshima, M., Ono, Y., Koike, Y. and Kajitani, T., Jpn. J. Appl. Phys. 39 (2000) L531.Google Scholar
3. Masset, A.C., Michel, C., Maigan, A., Hervieu, M., Toulemonde, O., Studer, F., Raveau, B. and Hejtmanek, J., Phys. Rev. B 62 (2000) 166.Google Scholar
4. Funahashi, R., Matsubara, I., Sodeoka, S., Appl. Phys. Lett. 76 (2000) 2385 Google Scholar
5. Sano, M., Horii, S., Matsubara, I., Funahashi, R., Shikano, M., Shimoyama, J. and Kishio, K., Jpn. J. Appl. Phys. 42 (2003) L198.Google Scholar
6. Horii, S., Matsubara, I., Sano, M., Fujie, K., Suzuki, M., Funahashi, R., Shikano, M., Shin, W., Murayama, N., Shimoyama, J. and Kishio, K., Jpn. J. Appl. Phys. 42 (2003) 7018.Google Scholar
7. Matsubara, I., Funahashi, R., Takeuchi, T. and Sodeoka, S., J. Appl. Phys. 90 (2001) 462.Google Scholar
8. Fujie, K., Horii, S., Matsubara, I., Shin, W., Murayama, N., Shimoyama, J., and Kishio, K., Mat. Res. Soc. Symp. Proc. 793 (2004) 317.Google Scholar
9. Okamoto, T., Horii, S., Uchikoshi, T., Suzuki, T.S., Sakka, Y., Funahashi, R., Ando, N., Sakurai, M., Shimoyama, J., and Kishio, K., Appl. Phys. Lett. 89 (2006) 081912.Google Scholar
10. Miyazaki, Y., Miura, T., Ono, Y. and Kajitani, T., J. Jpn. Soc. Powder Powder Metall. 50 (2003) 475. [in Japanese]Google Scholar
11. Miyazaki, Y., Suzuki, Y., Onoda, M., Ishii, Y., Morii, Y. and Kajitani, T., Jpn. J. Appl. Phys. 43 (2004) 6252.Google Scholar
12. Kumagai, T., Horii, S., Uchikoshi, T., Suzuki, T.S., Sakka, Y., Okamoto, T., Shimoyama, J. and Kishio, K., Jpn. J. Appl. Phys. 44 (2005) L1263.Google Scholar
13. Horii, S., Kumagai, T., Uchikoshi, T., Suzuki, T.S., Sakka, Y., Shimoyama, J. and Kishio, K., Scripta Materialia 57 (2007) 333.Google Scholar