Effect of chromium disorder on the thermoelectric properties of Layered-antiferromagnet CuCrS2

TL;DR

This study investigates how chromium atom disorder affects the thermoelectric properties of CuCrS2, revealing increased electrical conductivity and high thermoelectric power with disorder, while magnetic properties remain largely unchanged.

Contribution

It provides new insights into the impact of Cr-disorder on thermoelectric behavior and carrier localization in CuCrS2, a layered-antiferromagnetic compound.

Findings

Disorder increases electrical conductivity.

Thermoelectric power remains high and positive.

Magnetic properties are marginally affected.

Abstract

Layered-antiferromagnetic compound CuCrS2 has been prepared by different methods. The analysis of X-ray diffraction patterns of different samples gave significant amount of vacancy-disorder of Cr-atoms within the layers. Extended period of sintering above 9000C increases the transfer of Cr-atoms to the interstitial sites between the layers. This disorder has marginal effect on the Antiferromagnetic properties. The electrical conductivity is increased and the thermoelectric power remains positive and quite high between 150-400\muV/K in the paramagnetic state around room temperature with increase in disorder in different samples. We interpret the temperature dependence of electrical resistivity and thermoelectric power due to the localization of carriers by interstitial defects and the formation of magnetic polarons in the paramagnetic phase of CuCrS2.