
Author(s):
中村浩章、池田一昭、山口作太郎 H. Nakamura, K. Ikeda, S. Yamaguchi

Title:
強磁場中でのネルンスト素子の輸送現象とエネルギー変換 Transport Phenomena and Energy Conversion of the Nernst Element in a Strong Magnetic Field
Date of publication:
Nov. 1997

Key words:
indium antimonide, Nernst effect, Nernst coefficient, Nernst element, thermomagnetic conversion, transport coefficient, thermoelectric power, mobility, Boltzmann equation, parabolic band, phonon, scattering process, figure of merit, strong magnetic field

Abstract:
Electric generator by the Nernst effect in a strong magnetic field, which is called a Nernst element, was proposed in a few years ago. We have developed a measuring system of transport coefficients, which are, the thermoelectric coefficient alpha and the Nernst coefficient N, to find the Nernst element which has a good figure of merit. We obtained the temperature T and the magnetic field B dependence of both alpha and N of InSb, which has a high mobility and which is one of candidates of the Nernst elements, when 263K leq T leq 373K and B leq 4T. We measured two types of InSb samples, which we called sample A and sample B. Their carrier concentrations at 77K are n = 2.1 x l0^22 m^3 and n = 2.9 x l0^2l m^3, respectively. This measurement gives the following two important results: (i) Both alpha and N of sample B, which is in the intrinsic region near room temperature, are higher than those of sample A. (ii) the N of both samples are proportional to B up to 4 T. This fact is inconsistent with theoretical result, that is, N propto 1/B^2.

