Page 380 - Book Hosokawa Nanoparticle Technology Handbook

FUNDAMENTALS CH. 6 EVALUATION METHODS FOR PROPERTIES OF NANOSTRUCTURED BODY
surface properties. In addition, the square arrangement T.M. Hanssen, P. Boggild and F. Grey: J. Surf. Sci.
of probes enables the evaluation of the anisotropy of Jpn., 23, 740–752 (2002).
surface conduction [10]. [10] T. Kanagawa, R. Hobara, I. Matsuda, T. Tanikawa,
In the microprobe method, conductivity measure- A. Natori and S. Hasegawa: Phys. Rev. Lett., 91,
ments for one particle and infinitesimal parts of com- 036805-1-4 (2003).
posites will be possible with the control of probe
spacing and the subsequent improvement in resolving
power. Therefore, the microprobe method will be fur- 6.4.3 Thermoelectric properties
ther developed as a promising evaluation method for
electrical conduction properties of nanostructured Thermoelectric conversion is a direct energy conver-
materials. sion between thermal and electrical energies. It is based
on Seebeck effect and Peltier effect in the electrical
References conductors. Most of degenerated semiconductors and
special metals with high carrier density used for this
[1] D.J. Leary, J.O. Barnes and A.G. Jordan: purpose are called “thermoelectric materials.” The
J. Electrochem. Soc., 129, 1382–1386 (1982). energy conversion performance of the material is
[2] Jikken Kagaku Koza 9, Electricity and Magnetism, The defined by electrical and thermal transport coeffi-
Chemical Society of Japan (Ed.), Maruzen, 161 (1992). cients, more exactly, electrical conductivity , Seebeck
[3] T. Kawada: Chapter 8 in Kotai Dennki Kagaku, coefficient S and thermal conductivity .
Let us consider a closed circuit consisting of serial
Kodansha Scientific, Tokyo, 173–197 (2001).
connections of p- and n-type thermoelectric materials
[4] Y. Tanaka, M. Miyayama, M. Hibino and T. Kudo:
and under an electrical load as shown in Fig. 6.4.14a.
Solid State Ionics, 171, 33–39 (2004).
Applying forced temperature gradient T –T along
[5] For example: http://www.scribner.com/ H L
the sample length and assuming perfect thermal insu-
[6] I.M. Hodge, M.D. Ingram and A.R. West: J. Electroanal. lation, the thermal to electrical energy conversion
Chem., 74, 125–143 (1976). efficiency is expressed as follows [1].
[7] S.K. Kim, M. Miyayama and H. Yanagida: J. Ceram.
Soc. Jpn., 103, 315–318 (1995).
P T T 1 ZT 1
[8] H. Fujisawa, M. Shimizu, T. Horiuchi, T. Shiosaki and OUT H L ave (6.4.10)
K. Matsushige: Appl. Phys. Lett., 71, 416–418 (1997). Q IN T H 1 ZT ave T T H
L
[9] T. Hasegawa, I. Shiraki, F. Tanabe, R. Horiba,
2
T. Kanagawa, T. Tanikawa, I. Matsuda, C.L. Petersen, where T (T T )/2 and Z S /
ave H L

Figure 6.4.14
Schematics of thermoelectric power generation (a) and Peltier cooling (b).

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