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 (r) due to self-doping of the charge carriers and reduces thermal conductivity (j) due to increase in phonon scattering. The Seebeck coefficient (S) is p-type and remains nearly temperature independent with values between 150 lV/K and 450 lV/K due to electronic doping in different samples.

No abstract

No abstract

The results of low temperature thermoelectric power and the specific heat of 1T-VSe 2 (Vanadium diselenide) have been reported along with the electrical resistivity, and Hall coefficient of the compound. The Charge Density Wave (CDW) transition is observed near 110K temperature in all these properties. The Thermoelectric power has been measured from 15K to 300K spanning the incommensurate and commensurate CDW regions. We observed a weak anomaly at the CDW transition for the first time in the specific heat of VSe 2 . The linear temperature dependence of resistivity and thermoelectric power at higher temperatures suggests a normal metallic behavior and electron-phonon scattering above the CDW transition. The positive thermoelectric power and negative Hall coefficient along with strongly temperature dependent behavior in the CDW phase suggest a mixed conduction related to the strongly hybridized s-p-d bands in this compound.

No abstract