H. Nakamura, K. Ikeda, S. Yamaguchi
Transport Phenomena and Energy Conversion of the Nernst Element in a Strong Magnetic Field
Date of publication:
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
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.