NbS$_{3}$: A unique quasi one-dimensional conductor with three charge density wave transitions

TL;DR

This paper investigates NbS$_{3}$ phase II, revealing three charge-density wave transitions, including a high-temperature transition at 620-650 K, and explores their origins, coherence, and effects of uniaxial strain on these phenomena.

Contribution

The study uncovers a previously unreported high-temperature CDW transition and links the $T_{P2}$ transition to S vacancies, providing new insights into NbS$_{3}$'s CDW behavior.

Findings

Identification of a new high-temperature CDW transition at 620-650 K.

Evidence that S vacancies induce the $T_{P2}$ CDW transition.

Exceptional room-temperature coherence of the $T_{P1}$ CDW.

Abstract

Through transport, compositional and structural studies, we review the features of the charge-density wave (CDW) conductor of NbS$_{3}$ (phase II). We highlight three central results: 1) In addition to the previously reported CDW transitions at $T_{P1}$ = 360\,K and $T_{P2}$ = 150\,K, another CDW transition occurs at a much higher temperature $T_{P0}$ = 620-650\,K; evidence for the non-linear conductivity of this CDW is presented. 2) We show that CDW associated with the $T_{P2}$ - transition arises from S vacancies acting as donors. Such a CDW transition has not been observed before. 3) We show exceptional coherence of the $T_{P1}$-CDW at room-temperature. Additionally, we report on the effects of uniaxial strain on the CDW transition temperatures and transport.