Control of magnetic anisotropy in (Bi1-xPbx) 2(AE1-yREy)2Co2O z and fabrication of magnetically aligned bulks

T. Kumagai, S. Horii, T. Okamoto, J. Shimoyama, K. Kishio, T. Uchikoshi, Tohru Suzuki, Y. Sakka, M. Mikami, R. Funahashi

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

We have successfully fabricated two different types of grain-aligned bulks of thermoelectric Bismuth-based cobalt oxides using a magnetic grain-alignment process. The Pb-doping in (Bi2Sr2O4) 0.55CoO2, which shows an easy axis of magnetization parallel to the a-axis, was effective for enhancement of magnetic anisotropy along the a-axis, while the Ca-doping in [(Bi0.5Pb 0.5)2Sr2O4]0.55CoO 2 converted the easy axis along the a-axis to that along the c-axis. Moreover, the magnetic anisotropy along the c-axis was enhanced by the partial Pr-doping for the Ca sites. The changes of their crystal structures revealed that distortion of the block layer was arisen from the substitution of the Ca-doping or the co-doping of Ca and Pr for the Sr sites in [(Bi 0.5Pb0.5)2Sr2O4] 0.55CoO2, leading to the changes of their magnetic anisotropies through locally structural distortion of the CoO2 layers. The c-axis and a-axis grain-aligned bulks were fabricated by the slip-casting method under a magnetic field of 10 T for [(Bi0.5Pb 0.5)2(Ca0.8Pr0.2)2O 4]pCoO2 and [(Bi0.75Pb 0.25)2Sr2O4]0.55CoO 2, respectively. Especially for the c-axis grain-aligned bulk, microstructure observation showed highly grain-oriented, and large reduction of resistivity was observed in a perpendicular direction to the applied field. The control of the easy axis of magnetization by a crystallochemical process is useful for the application of a magnetic grain-alignment process.

Original languageEnglish
Title of host publicationElectroceramic Materials and Applications - Proceedings of the 6th Pacific Rim Conference on Ceramic and Glass Technology
Pages291-301
Number of pages11
Publication statusPublished - 2006 Dec 1
Externally publishedYes
Event6th Pacific Rim Conference on Ceramic and Glass Technology - Maui, Hawaii, United States
Duration: 2005 Sep 112005 Sep 16

Publication series

NameCeramic Transactions
Volume196
ISSN (Print)1042-1122

Other

Other6th Pacific Rim Conference on Ceramic and Glass Technology
CountryUnited States
CityMaui, Hawaii
Period05/9/1105/9/16

Fingerprint

Magnetic anisotropy
Doping (additives)
Fabrication
Magnetization
Bismuth
Cobalt
Casting
Substitution reactions
Crystal structure
Magnetic fields
Microstructure
Oxides

ASJC Scopus subject areas

  • Ceramics and Composites
  • Materials Chemistry

Cite this

Kumagai, T., Horii, S., Okamoto, T., Shimoyama, J., Kishio, K., Uchikoshi, T., ... Funahashi, R. (2006). Control of magnetic anisotropy in (Bi1-xPbx) 2(AE1-yREy)2Co2O z and fabrication of magnetically aligned bulks. In Electroceramic Materials and Applications - Proceedings of the 6th Pacific Rim Conference on Ceramic and Glass Technology (pp. 291-301). (Ceramic Transactions; Vol. 196).

Control of magnetic anisotropy in (Bi1-xPbx) 2(AE1-yREy)2Co2O z and fabrication of magnetically aligned bulks. / Kumagai, T.; Horii, S.; Okamoto, T.; Shimoyama, J.; Kishio, K.; Uchikoshi, T.; Suzuki, Tohru; Sakka, Y.; Mikami, M.; Funahashi, R.

Electroceramic Materials and Applications - Proceedings of the 6th Pacific Rim Conference on Ceramic and Glass Technology. 2006. p. 291-301 (Ceramic Transactions; Vol. 196).

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Kumagai, T, Horii, S, Okamoto, T, Shimoyama, J, Kishio, K, Uchikoshi, T, Suzuki, T, Sakka, Y, Mikami, M & Funahashi, R 2006, Control of magnetic anisotropy in (Bi1-xPbx) 2(AE1-yREy)2Co2O z and fabrication of magnetically aligned bulks. in Electroceramic Materials and Applications - Proceedings of the 6th Pacific Rim Conference on Ceramic and Glass Technology. Ceramic Transactions, vol. 196, pp. 291-301, 6th Pacific Rim Conference on Ceramic and Glass Technology, Maui, Hawaii, United States, 05/9/11.
Kumagai T, Horii S, Okamoto T, Shimoyama J, Kishio K, Uchikoshi T et al. Control of magnetic anisotropy in (Bi1-xPbx) 2(AE1-yREy)2Co2O z and fabrication of magnetically aligned bulks. In Electroceramic Materials and Applications - Proceedings of the 6th Pacific Rim Conference on Ceramic and Glass Technology. 2006. p. 291-301. (Ceramic Transactions).
Kumagai, T. ; Horii, S. ; Okamoto, T. ; Shimoyama, J. ; Kishio, K. ; Uchikoshi, T. ; Suzuki, Tohru ; Sakka, Y. ; Mikami, M. ; Funahashi, R. / Control of magnetic anisotropy in (Bi1-xPbx) 2(AE1-yREy)2Co2O z and fabrication of magnetically aligned bulks. Electroceramic Materials and Applications - Proceedings of the 6th Pacific Rim Conference on Ceramic and Glass Technology. 2006. pp. 291-301 (Ceramic Transactions).
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AU - Kishio, K.

AU - Uchikoshi, T.

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