Hostname: page-component-cd9895bd7-hc48f Total loading time: 0 Render date: 2024-12-24T02:33:15.574Z Has data issue: false hasContentIssue false

Thermoelectric properties and spark plasma sintering of doped YB22C2N

Published online by Cambridge University Press:  31 January 2011

Takao Mori*
Affiliation:
National Institute for Materials Science, Namiki 1-1, Tsukuba, 305-0044 Japan
*
a)Address all correspondence to this author. e-mail: [email protected]
Get access

Abstract

YB22C2N is one of a series of rare earth borocarbonitrides and is potentially the long awaited n-type counterpart to boron carbide. We conducted studies on YB22C2N spark plasma sintered with additions of YB4 and YB25C, including the investigations of the densification process and the thermoelectric properties of the material. We discovered that a small amount of dopants can lower the starting temperature of densification during spark plasma sintering (SPS). Variations of pressure and temperature during the sintering process are also found to have an effect. Electrical conductivity of the dense samples has increased due to insertion of metal borides and also because of the improvement of the relative density. At the same time, only a slight reduction was observed for the Seebeck coefficient leading to an important improvement of power factor. The highest density of more than 95% was achieved with 5 wt% of YB25(C) dopant.

Type
Articles
Copyright
Copyright © Materials Research Society 2010

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.Mori, T.Higher boridesHandbook on the Physics and Chemistry of Rare Earths Vol. 38 edited by K.A Gschneidner, Jr., J-C. Bunzli, and V. Pecharsky (Elsevier, Amsterdam 2008)105Google Scholar
2.Mori, T.High temperature thermoelectric properties of B12 icosahedral cluster-containing rare earth boride crystals. J. Appl. Phys. 97, (09)3703 (2005)CrossRefGoogle Scholar
3.Mori, T., Nishimura, T.Thermoelectric properties of homologous p- and n-type boron-rich borides. J. Solid State Chem. 179, (9)2908 (2006)CrossRefGoogle Scholar
4.Mori, T., Nishimura, T., Yamaura, K., Takayama-Muromachi, E.High temperature thermoelectric properties of a homologous series of n-type boron icosahedra compounds: A possible counterpart to p-type boron carbide. J. Appl. Phys. 101, (09)3714 (2007)CrossRefGoogle Scholar
5.Kanno, Y., Kawase, K., Nakano, K.Additive effect on sintering of boron carbide. Yogyo-Kyokai-Shi 95, 1137 (1987)CrossRefGoogle Scholar
6.Roy, T.K., Subramanian, C., Suri, A.K.Presureless sintering of boron carbide. Ceram. Int. 32, (3)227 (2006)CrossRefGoogle Scholar
7.Cai, K-f., Nan, C-W., Paderno, Y., McLachlan, D.S.Effect of titanium carbide addition on the thermoelectric properties of B4C ceramics. Solid State Commun. 115, (10)523 (2000)CrossRefGoogle Scholar
8.Zhang, F., Leithe-Jasper, A., Xu, J., Mori, T., Matsui, Y., Tanaka, T., Okada, S.Novel rare earths boron-rich solids. J. Solid State Chem. 159, (1)174 (2001)CrossRefGoogle Scholar
9.Zhang, F.X., Xu, F.F., Leithe-Jasper, A., Mori, T., Tanaka, T., Sato, A., Salamakha, P., Bando, Y.Incorporation of carbon atoms in rare earths boron-rich solids and formation of superstructures. J. Alloys Compd. 337, 120 (2002)CrossRefGoogle Scholar
10.Fahrenholtz, W.G., Hilmas, G.E., Zhang, S.C., Zhu, S.Pressureless sintering of zirconium diboride: Particle size and additive effects. J. Am. Ceram. Soc. 91, (5)1398 (2008)CrossRefGoogle Scholar
11.Sato, M., Nanko, M., Matsumaru, K., Ishizaki, K.Homogeneity in sintering of fine Ni-20Cr powder by pulsed electric current sintering (PECS) process. Adv. Tech. of Mater. Mater. Proc. J. 8, (1)101 (2006)Google Scholar
12.Anselmi-Tamburini, U., Garay, J.E., Munir, Z.A.Fundamental investigations on the spark plasma sintering/synthesis process. III. Current effect on reactivity. Mater. Sci. Eng., A 394, 132 (2005)CrossRefGoogle Scholar