Zhang, XuNguyen, HoangZhang, XiangAjayan, Pulickel M.Wen, JianguoEspinosa, Horacio D.2022-12-132022-12-132022Zhang, Xu, Nguyen, Hoang, Zhang, Xiang, et al.. "Atomistic measurement and modeling of intrinsic fracture toughness of two-dimensional materials." <i>Proceedings of the National Academy of Sciences,</i> 119, no. 45 (2022) PNAS: https://doi.org/10.1073/pnas.2206756119.https://hdl.handle.net/1911/114112Quantifying the intrinsic mechanical properties of two-dimensional (2D) materials is essential to predict the long-term reliability of materials and systems in emerging applications ranging from energy to health to next-generation sensors and electronics. Currently, measurements of fracture toughness and identification of associated atomistic mechanisms remain challenging. Herein, we report an integrated experimental–computational framework in which in-situ high-resolution transmission electron microscopy (HRTEM) measurements of the intrinsic fracture energy of monolayer MoS 2 and MoSe 2 are in good agreement with atomistic model predictions based on an accurately parameterized interatomic potential. Changes in crystalline structures at the crack tip and crack edges, as observed in in-situ HRTEM crack extension tests, are properly predicted. Such a good agreement is the result of including large deformation pathways and phase transitions in the parameterization of the inter-atomic potential. The established framework emerges as a robust approach to determine the predictive capabilities of molecular dynamics models employed in the screening of 2D materials, in the spirit of the materials genome initiative. Moreover, it enables device-level predictions with superior accuracy (e.g., fatigue lifetime predictions of electro- and opto-electronic nanodevices).engThis article is distributed under Creative Commons Attribution-NonCommercial-NoDerivatives License 4.0 (CC BY-NC-ND).Journal articlepnas-2206756119https://doi.org/10.1073/pnas.2206756119