The Elastic Moduli of 2D Transition Metal Dichalcogenides

The elastic moduli of four transition metal dichalcogenides (TMDs) were studied using an atomic force microscope (AFM). Nanoindentation was performed using the AFM to generate force curves which were analyzed using the Oliver-Pharr method. The TMDs tested were Molybdenum Disulfide (MoS₂), Rhenium Diselenide (ReSe₂), Rhenium Disulfide (ReS₂), and Tungsten Diselenide (WSe₂) which had a Young’s modulus values of 71.9 GPa, 28.3 GPa, 56.3 GPa, and 40.4 GPa respectively. The results are significantly lower than the expected values for the elastic moduli obtained from density functional theory (DFT) calculations.