Semiconducting nature and thermal transport studies of ZrTe3

TL;DR

This study investigates the electrical and thermal transport properties of polycrystalline ZrTe3, revealing semiconducting behavior, persistent charge density wave signatures, and the influence of disorder on transport mechanisms.

Contribution

It provides new insights into the transport properties of polycrystalline ZrTe3, highlighting the effects of disorder and the dominance of polaron hopping in thermal and electrical conduction.

Findings

Polycrystalline ZrTe3 exhibits semiconducting behavior.

Charge density wave signatures are observed in thermal and Seebeck measurements.

Disorder suppresses the CDW transition and influences transport mechanisms.

Abstract

We report electrical and thermal transport properties of polycrystalline ZrTe3. The polycrystalline sample shows semiconducting behavior in contrast to the established semi-metallic character of the compound. However the charge density wave (CDW) transition remains intact and its clear signatures are observed in thermal conductivity and Seebeck coefficient, in the wide temperature range 50 - 100 K. The thermal conductivity points to additional scattering from the low frequency phonons (phonon softening) in the vicinity of CDW transition. The transport in the polycrystalline compounds is governed by smaller size polarons in the variable range hopping (VRH) region. However, the increasing disorder in polycrystalline compounds suppresses the CDW transition. The VRH behavior is also observed in the Seebeck coefficient data in the similar temperature range. The Seebeck coefficient suggests a competition between the charge carriers (electrons and hole).