Structural Phase Transformation in Strained Monolayer MoWSe<sub>2</sub> Alloy
POSTER
Abstract
Molecular dynamics (MD) simulations are performed to examine atomistic mechanisms of defect formation and crack propagation in a strained monolayer MoWSe2 alloy. The system consists of a 1.0 m x 1.0 m MoSe2 monolayer with a pre-crack and random patches of WSe2. Under strain, the crack meanders as it propagates through the system and branches into two daughter cracks when it crosses the MoSe2/WSe2 interface and enters the WSe2 patches. The most dramatic change occurs in the process zone around the crack tip, where large stress concentration and the resulting biaxial tensile strain trigger an irreversible local structural phase transformation from the ground state 2H crystal structure to the 1T crystal structure. This is consistent with experimental observations in an MoWSe2 alloy.
*This work was supported as part of the Computational Materials Sciences Program funded by the U.S. Department of Energy, Office of Science, and Basic Energy Sciences, under Award Number DE-SC00014607. The simulations were performed at the Argonne Leadership Computing Facility under the DOE INCITE program
Presenters
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Pankaj Rajak
- Univ of Southern California
- University of Southern California
- Mork Family Department of Chemical Engineering and Materials Science, Univ of Southern California