In:
Physica Scripta, IOP Publishing, Vol. 98, No. 7 ( 2023-07-01), p. 075002-
Abstract:
It is well known that monolayer transition-metal dichalcogenides (MX 2 , M = Mo, W and X = S, Se, Te) could exist in three common structures, i.e. 1 T , 1 T ′ , and 1 H phases. In order to reveal their possible phase transitions driven by biaxial strain, we use first-principles calculations to determine the energy landscapes associated with these three phases. Due to its intrinsic dynamical instability, the centrosymmetric 1 T phase is known to be metastable and will transform into the 1 T ′ phase where pairs of metal atoms pull together toward each other. Moreover, controlling the metallic 1 T ′ and semiconducting 1 H phases is of particular interest as this can introduce novel opportunities in a series of applications. When a biaxial strain is simultaneously compressed along the zigzag direction and stretched along the armchair direction, phase transitions from 1 H to 1 T ′ have occurred in MSe 2 and MoTe 2 , but for MSe 2 the biaxial strain is much difficult to realize in experiments. For WTe 2 , the 1 T ′ structure will transform into the 1 H form when a biaxial strain is just compressed along the armchair direction. The transitions between 1 H and 1 T ′ phases could be attributed to the changes of metal-chalcogen bonds along the armchair direction by analyzing the Crystal Orbital Hamilton Population. Only half M-X bonds along the armchair direction is the main factor, because their lengths are robust in 1 T ′ phase and decrease in 1 H form with the tensile strain applied along the armchair direction. Our findings provide a guideline for the phase engineering of transition-metal dichalcogenides with biaxial strain.
Type of Medium:
Online Resource
ISSN:
0031-8949
,
1402-4896
DOI:
10.1088/1402-4896/acd81b
Language:
Unknown
Publisher:
IOP Publishing
Publication Date:
2023
detail.hit.zdb_id:
1477351-X
