Jump to main content
Jump to site search

Issue 16, 2017
Previous Article Next Article

Thermoelectric properties of CuGa1−xMnxTe2: power factor enhancement by incorporation of magnetic ions

Author affiliations

Abstract

Chalcopyrite CuGaTe2 is under research for its high thermoelectric performance. Different routes have been investigated recently for enhancing its thermoelectric parameters. In this work we report the synthesis of chalcopyrite CuGa1−xMnxTe2 (x = 0.0, 0.01, 0.02, and 0.03) by a solid state method and through which an enhanced power factor was obtained. The samples were characterized for electrical, thermal and thermoelectric transport properties in the temperature range 325–870 K after performing stability analysis using TG-DTA data. XRD patterns confirm a phase pure tetragonal structure for all nominal compositions with the space group I[4 with combining macron]2d. The electrical conductivity σ increases drastically by Mn2+ doping which increases the hole carriers, while the Seebeck coefficient S still retains large positive values. As a result, the power factor of CuGa0.99Mn0.01Te2 reaches 1.55 mW K−2 m−1 at 718 K. Calculations using the relationship of S and ln σ suggest that the power factor observed for Mn-doped samples is higher than that expected for CuGaTe2 with optimized carrier concentration, suggesting that the Mn-doping brings additional effects other than simple carrier tuning. The total thermal conductivity is reduced by Mn doping, with a minimum thermal conductivity of 1.6 W m−1 K−1 for the x = 0.01 sample. The maximum value for ZT reached at 870 K was 0.83, which is more than 40% enhancement as compared to that of pure CuGaTe2. Strong interactions between the magnetic moments of Mn and charge carriers are inferred by the large negative Weiss temperature in the magnetic susceptibility and distinct anomalous Hall effect, the latter of which develops in accordance with the increase of magnetization at low temperature. These results suggest that the carrier–magnetic moment interaction plays an essential role in the enhancement of the thermoelectric properties of CuGa1−xMnxTe2.

Graphical abstract: Thermoelectric properties of CuGa1−xMnxTe2: power factor enhancement by incorporation of magnetic ions

Back to tab navigation
Please wait while Download options loads

Supplementary files

Publication details

The article was received on 27 Dec 2016, accepted on 16 Mar 2017 and first published on 16 Mar 2017


Article type: Paper
DOI: 10.1039/C6TA11120C
Citation: J. Mater. Chem. A, 2017,5, 7545-7554
  •   Request permissions

    Thermoelectric properties of CuGa1−xMnxTe2: power factor enhancement by incorporation of magnetic ions

    F. Ahmed, N. Tsujii and T. Mori, J. Mater. Chem. A, 2017, 5, 7545
    DOI: 10.1039/C6TA11120C

Search articles by author