Thermoelectric properties of Mn doped BiCuSeO

Das, Sayan and Valiyaveettil, Suneesh Meledath and Chen, Kuei-Hsien and Suwas, Satyam and Mallik, Ramesh Chandra (2019) Thermoelectric properties of Mn doped BiCuSeO. In: MATERIALS RESEARCH EXPRESS, 6 (8).

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Abstract

BiCuSeO is a promising thermoelectric material having earth-abundant non-toxic constituents and favourable thermoelectric properties like ultra-low thermal conductivity. In this study, Mn+2 has been introduced at the Bi+3 site to increase hole concentration as well as Seebeck coefficient, through aliovalent doping and magnetic impurity incorporation respectively. Samples were prepared through two-step solid state synthesis with the composition Bi1-xMnxCuSeO(x = 0.0, 0.04, 0.06, 0.08, 0.10 and 0.12). X-ray diffraction patterns confirmed the tetragonal (space group: P4/ nmm) crystal structure of BiCuSeO as well as phase purity of the samples. The Seebeck coefficient and electrical resistivity had a decreasing trend with increasing doping fraction owing to the generation of charge carriers. The samples with x = 0.04 and 0.06 showed temperature independent Seebeck coefficient above 523 K, which is a signature of small polaron hopping. While the Seebeck coefficient of the samples with x = 0.08, 0.10 and 0.12 increased above 523 K due to the combination of localized and extended states. The thermal conductivity was dominated by the lattice part of the thermal conductivity. As a result of moderate Seebeck coefficient and low electrical resistivity, the highest power factor of 0.284 mW m(-1)-K-2 was obtained for the Bi Mn-0.92 ( 0.08) CuSeO at 773 K, leading to a maximum zT of 0.4 at 773.

Item Type:	Journal Article
Publication:	MATERIALS RESEARCH EXPRESS
Publisher:	IOP PUBLISHING LTD
Additional Information:	The copyright for this article belongs to IOP PUBLISHING LTD
Keywords:	seebeck coefficient; electrical resistivity; thermal conductivity
Department/Centre:	Division of Mechanical Sciences > Materials Engineering (formerly Metallurgy) Division of Physical & Mathematical Sciences > Physics
Date Deposited:	01 Jul 2019 11:19
Last Modified:	01 Jul 2019 11:19
URI:	http://eprints.iisc.ac.in/id/eprint/62761

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