Local structure memory effects in the polar and nonpolar phases of MoTe2

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

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Original languageEnglish
Article number094101
Journal / PublicationPhysical Review B
Volume103
Issue number9
Online published1 Mar 2021
Publication statusPublished - 1 Mar 2021
Externally publishedYes

Abstract

We use total scattering to study the reversible transition between the polar 1T′ and nonpolar Td phases of layered MoTe2 taking place at 240 K. Whereas, macroscopically, the transition appears to be first order, locally, it is not. In particular, a great deal of the stacking sequence of Te-Mo-Te layers characteristic of the polar 1T′ phase persists locally in the nonpolar Td phase, and vice versa, over a broad temperature range extending about 100 K both below and above the transition. The intermixing ratio for the two sequences evolves gradually across the transition temperature, consistent with a second-order transition behavior. The presence of coexisting local polar and nonpolar regions and the resulting variety of internal interfaces where the spatial inversion symmetry is broken may be behind some of the unusual electronic properties of Td-MoTe2, including its putative type-II Weyl semimetal state.