The thermoelectric figure of merit (ZT) of the layered antiferromagnetic compound CuCrS 2 is further improved with increase in the Cr-vacancy disorder on sintering above 900°C. X-ray photoelectron spectroscopy and x-ray diffraction refinement results for different samples show that the chromium atoms are transferred from the filled layers to the vacant sites between the layers. This atomic disorder increases the electrical conductivity (σ) due to self-doping of the charge carriers and reduces thermal conductivity (κ) due to increase in phonon scattering. The Seebeck coefficient (S) is p-type and remains nearly temperature independent with values between 150 μV/K and 450 μV/K due to electronic doping in different samples.
Bibliographical noteFunding Information:
We acknowledge Advanced Instrumentation Research Facility of JNU for providing experimental facilities for this work. G.C.T. and T.S.T. also acknowledge the Council of Scientific and Industrial Research (CSIR), India for financial support.
- Thermoelectric materials
- electrical and thermal conduction in crystalline metals and alloys
- magnetic polarons
- transition-metal compounds