Mechanical Properties and Strain Transfer Behavior of Molybdenum Ditelluride (MoTe2) Thin Films

Chowdhury, Shoieb Ahmed; Inzani, Katherine; Peña, Tara; Dey, Aditya; Wu, Stephen M.; Griffin, Sinéad M.; Askari, Hesam

Abstract

Transition metal dichalcogenides (TMDs) offer superior properties over conventional materials in many areas such as in electronic devices. In recent years, TMDs have been shown to display a phase switching mechanism under the application of external mechanical strain, making them exciting candidates for phase change transistors. Molybdenum ditelluride (MoTe2) is one such material that has been engineered as a strain-based phase change transistor. In this work, we explore various aspects of the mechanical properties of this material by a suite of computational and experimental approaches. First, we present parameterization of an interatomic potential for modeling monolayer as well as multilayered MoTe2 films. For generating the empirical potential parameter set, we fit results from density functional theory calculations using a random search algorithm known as particle swarm optimization. The potential closely predicts structural properties, elastic constants, and vibrational frequencies of MoTe2 indicating a reliable fit. Our simulated mechanical response matches earlier larger scale experimental nanoindentation results with excellent prediction of fracture points. Simulation of uniaxial tensile deformation by molecular dynamics shows the complete non-linear stress-strain response up to failure. Mechanical behavior, including failure properties, exhibits directional anisotropy due to the variation of bond alignments with crystal orientation. Furthermore, we show the deterioration of mechanical properties with increasing temperature. Finally, we present computational and experimental evidence of an extended c-axis strain transfer length in MoTe2 compared to TMDs with smaller chalcogen atoms.

Citation

Chowdhury, S. A., Inzani, K., Peña, T., Dey, A., Wu, S. M., Griffin, S. M., & Askari, H. (2022). Mechanical Properties and Strain Transfer Behavior of Molybdenum Ditelluride (MoTe2) Thin Films. Journal of Engineering Materials and Technology, 144(1), Article 011006. https://doi.org/10.1115/1.4051306

• Journal Article Type: Article
• Acceptance Date: May 20, 2021
• Online Publication Date: Jun 15, 2021
• Publication Date: Jan 1, 2022
• Deposit Date: Mar 19, 2025
• Journal: Journal of Engineering Materials and Technology
• Print ISSN: 0094-4289
• Electronic ISSN: 1528-8889
• Publisher: American Society of Mechanical Engineers
• Peer Reviewed: Peer Reviewed
• Volume: 144
• Issue: 1
• Article Number: 011006
• DOI: https://doi.org/10.1115/1.4051306
• Keywords: transition metal dichalcogenides, MoTe2, molecular dynamics, interatomic potential, mechanical properties, strain transfer
• Public URL: https://nottingham-repository.worktribe.com/output/46736109
• Publisher URL: https://asmedigitalcollection.asme.org/materialstechnology/article/144/1/011006/1109770/Mechanical-Properties-and-Strain-Transfer-Behavior
• Additional Information: Paper No: MATS-21-1078