Study Of Ball Milled Bismuth Telluride Composites Reinforced With MWCNTs For Thermoelectric behaviour

¹Electron and Ion Microscopy Division, CSIR-National Physical Laboratory, New Delhi 110012, India

²Department of Physics, Punjab University, Chandigarh 160014, India

Adv. Mater. Lett., 2016, 7 (7), pp 549-554

DOI: 10.5185/amlett.2016.6112

Publication Date (Web): Jun 12, 2016

Copyright © IAAM-VBRI Press

E-mail: skpnagali@gmail.com

Abstract

Thermoelectric properties of n-type bismuth telluride and its nanocomposite reinforced with different concentration of multi wall carbon nanotubes (MWCNTs) are reported. Nanocomposites of bismuth telluride with MWCNTs were synthesized by using high energy ball milling followed by spark plasma sintering (SPS). MWCNTs reinforced nanocomposites of bismuth telluride resulted improvement in its figure of merit ZT from 0.76 (for Bi₂Te₃) to 0.85 (for Bi₂Te₃ + 2%MWCNTs) at 473K temperature. Thermoelectric parameters of nanocomposites of Bi₂Te₃ were characterized by Laser Flash Technique. The improvements found in ZT value may be due to decrease in thermal conductivity of the nanocomposites. Concentration of MWCNTs in bismuth telluride leads to dampening the phonon propagation with addition to the interface scattering of phonons from phase boundaries as well as grain boundaries which leads to decrease in thermal conductivity.

Keywords

Ball milling, bismuth telluride, microstructure, spark plasma sintering, thermoelectric properties.