Mudgel, Monika and Awana, V. P. S. and Lal, R. and Kishan, H. and Chandra, L. S. Sharth and Ganesan, V. and Narlikar, A. V. and Bhalla, G. L. (2008) Anomalous thermoelectric power of the Mg1−xAlxB2 system with x = 0.0–1.0. Journal Of Physics: Condensed Matter, 20 (9). 095205-1 - 095205-6 . ISSN 0953-8984

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Abstract

The thermoelectric power, S(T), of the Mg1−xAlxB2 system has been measured for x = 0.0, 0.1, 0.2, 0.4, 0.6, 0.8 and 1.0. X-ray diffraction, resistivity and magnetization measurements are also presented. It has been found that the thermoelectric power is positive for x≤0.4 and is negative for x≥0.6 over the entire temperature range studied up to 300 K. The thermoelectric power of x≤0.4 samples vanishes discontinuously below a certain temperature, implying the existence of superconductivity. In general, the magnitude of the thermoelectric power increases with temperature up to a certain temperature, and then it starts to decrease towards a zero baseline. In order to explain the observed behavior of the thermoelectric power, we have used a model in which diffusion and phonon drag processes are combined, by using a phenomenological interpolation between the low and high temperature behaviors of the thermoelectric power. The model considered provides an excellent fit to the observed data. It is further found that Al doping enhances the Debye temperature.

Item Type:	Article
Additional Information:	Copyright for this article belongs to M/s IOP Publishing.
Subjects:	Physics
Divisions:	UNSPECIFIED
Depositing User:	Ms Neetu Chandra
Date Deposited:	10 Jan 2013 11:50
Last Modified:	10 Jan 2013 11:50
URI:	http://npl.csircentral.net/id/eprint/945

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