Hostname: page-component-586b7cd67f-t8hqh Total loading time: 0 Render date: 2024-12-01T03:04:35.334Z Has data issue: false hasContentIssue false
  • English
  • Français

Single crystallization of Ba8AlxSi46−x clathrate for improvement of thermoelectric properties

Published online by Cambridge University Press:  27 July 2011

Naoki Mugita ,
Yusuke Nakakohara ,
Ryo Teranishi  and
Shinji Munetoh
Naoki Mugita*
Affiliation:
Department of Materials Science and Engineering, Kyushu University, Fukuoka 819-0395, Japan
Yusuke Nakakohara
Affiliation:
Department of Materials Science and Engineering, Kyushu University, Fukuoka 819-0395, Japan
Ryo Teranishi
Affiliation:
Department of Materials Science and Engineering, Kyushu University, Fukuoka 819-0395, Japan
Shinji Munetoh
Affiliation:
Department of Materials Science and Engineering, Kyushu University, Fukuoka 819-0395, Japan
*
a)Address all correspondence to this author. e-mail: [email protected]
Get access

Abstract

We have synthesized single- and polycrystal Ba8AlxSi46−x clathrates to compare their thermoelectric properties. Single-crystal sample was prepared by Czochralski method in an argon atmosphere. Polycrystal sample was prepared by arc melting and annealed at 850 °C for 100 h in an argon atmosphere. The Seebeck coefficients of single- and polycrystal Ba8Al12Si34 at 500 °C were 44.5 and 53.0 μV/K, respectively. The Seebeck coefficients of both samples were almost the same because the Seebeck coefficients depend on carrier concentration, which is related to aluminum content. The electrical resistivity of the single-crystal sample with 0.49 mΩcm was lower than that of the polycrystal sample with 0.95 mΩcm because of the reduction of electron scattering. Therefore, the power factor of the single-crystal sample with 4.0 × 10−4 V2/K2Ωm was higher than that of the polycrystal sample with 3.0 × 10−4 V2/K2Ωm at 500 °C. It is suggested that single crystallization is efficient for improvement of the thermoelectric property in the Ba8AlxSi46−x clathrate.

Keywords

ThermoelectricCrystal growth
Type
Articles
Information
Journal of Materials Research , Volume 26 , Issue 15: Focus Issue: Advances in Thermoelectric Materials , 14 August 2011 , pp. 1857 - 1860
Copyright
Copyright © Materials Research Society 2011

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

REFERENCES

1.Wright, D.A.: Thermoelectric properties of bismuth telluride and its alloys. Nature 181, 834 (1958).CrossRefGoogle Scholar
2.Ocio, M. and Albany, H.J.: Band structure parameters in Pb0.7Sn0.3Te and Pb0.5Sn0.5Te. Phys. Lett. A 30, 169 (1969).CrossRefGoogle Scholar
3.Heller, M.W., Nasby, R.D., and Jhonson, R.T.: Electrical transport properties of SiGe alloys doped with As, P and As+P. J. Appl. Phys. 47, 4113 (1976).CrossRefGoogle Scholar
4.Nolas, G.S., Cohn, J.L., Slack, G.A., and Schujman, S.B.: Semiconducting Ge clathrates: Promising candidates for thermoelectric applications. Appl. Phys. Lett. 73, 178 (1998).CrossRefGoogle Scholar
5.Nolas, G.S.: Semiconducter clathrates: A PGEC system with potential for thermoelectric applications, in Thermoelectric Materials 1998-The Next Generation Materials for Small-Scale Refrigeration and Power Generation Applications, edited by Tritt, T.M., Kanatzidis, M.G., Mahan, G.D. and Lyon, H.B. Jr. (Mater. Res. Soc. Symp. Proc. 545, Warrendale, PA, 1999), p. 435.Google Scholar
6.Schujman, S.B., Nolas, G.S., Young, R.A., Lind, C., Wilkinson, A.P., Slack, G.A., Patschke, R., Kantzidis, M.G., Ulutagay, M., and Hwu, S.J.: Structural analysis of Sr8Ga16Ge30 clathrate compound. J. Appl. Phys. 87, 1529 (2000).CrossRefGoogle Scholar
7.Slack, G.A.: Design concepts for improved thermoelectric materials, in Thermoelectric Materials-New Directions and Approaches, edited by Tritt, T.M., Kanatzidis, M.G., Lyon, H.B. Jr., and Mahan, G.D. (Mater. Res. Soc. Symp. Proc. 478, Pittsburgh, PA, 1997), p. 47.Google Scholar
8.Kishimoto, K., Ikeda, N., Akai, K., and Koyanagi, T.: Synthesis and thermoelectric properties of silicon clathrates Sr8AlxGa16-xSi30 with the type-I and type-VIII structures. Appl. Phys. Exp. 1, 031201 (2008).CrossRefGoogle Scholar
9.Okamoto, N.L., Kishida, K., Tanaka, K., and Inui, H.: Effect of In additions on the thermoelectric properties of the type-I clathrate compound Ba8Ga16Ge30. J. Appl. Phys. 101, 113525 (2007).CrossRefGoogle Scholar
10.Condron, C.L., Kauzlarich, S.M., and Nolas, G.S.: Structure and thermoelectric characterization of AxBa8-xAl14Si31(A = Sr, Eu) single crystals. Inorg. Chem. 46, 2556 (2007).CrossRefGoogle Scholar
11.Uemura, T., Akai, K., Koga, K., Tanaka, T., Kurisu, H., Yamamoto, S., Kishimoto, K., Koyanagi, T., and Matsuura, M.: Electronic structure and thermoelectric properties of clathrate compounds Ba8AlxGe46−x. J. Appl. Phys. 104, 013702 (2008).CrossRefGoogle Scholar
12.Nenghabi, E.N. and Myles, C.W.: First-principles calculations of the structural, electronic and vibrational properties of the clathrates Ba8Al16Ge30 and Ba8Al16Si30. J. Phys. Condens. Matter 20, 415214 (2008).CrossRefGoogle Scholar