Strain-induced splitting of the CCDW-NCCDW phase transition in 1T-TaS$_2$

TL;DR

This study investigates how uniaxial and biaxial tensile strain affect the resistivity and phase transition temperatures in 1T-TaS$_2$, revealing strain-induced phase splitting and modifications in CDW states.

Contribution

It demonstrates the strain-induced splitting of the CCDW-NCCDW transition and characterizes the anisotropic effects on resistivity and phase behavior in 1T-TaS$_2$.

Findings

Uniaxial strain causes phase transition temperature splitting exceeding 10 K.

Biaxial strain decreases the CCDW-NCCDW transition temperature by up to 20 K.

Resistivity components increase similarly under uniaxial tensile strain.

Abstract

The effects of uniaxial and biaxial tensile strain on the $\rho_{xx}$ and $\rho_{yy}$ components of the resistivity tensor, and the commensurable-nearly commensurate CDW (CCDW-NCCDW) transition temperature in 1T-TaS$_2$ are studied. At room temperature, uniaxial tensile strain increases the resistivity tensor components by a comparable magnitude both parallel and perpendicular to the strain axis. In the case of biaxial strain, up to 20~K decrease in the CCDW-NCCDW phase transition temperature is observed. In the case of uniaxial strain, a new phase with two different CCDW-NCCDW phase transition temperatures is observed, the splitting exceeds 10 K. The occurrence of such a phase is associated with the transition of the CDW into the commensurate state along the tensile strain direction while maintaining nearly commensurability along the perpendicular one. The results allow to justify various models widely used in analysis of transport properties of 1T-TaS$_2$ in commensurate and nearly commensurate states.