Anomalous fracture in two-dimensional rhenium disulfide

Area of Science:

• Materials Science
• Nanotechnology
• Solid Mechanics

Background:

• Low-dimensional materials often display distinct mechanical properties compared to their bulk counterparts.
• Understanding fracture mechanisms in two-dimensional (2D) materials is crucial for their application.

Purpose of the Study:

• To investigate the atomic-scale fracture processes in 2D rhenium disulfide (ReS2).
• To identify previously unidentified fracture phenomena in 2D materials.
• To elucidate the origin of brittleness in 2D materials.

Main Methods:

• Direct transmission electron microscopy (TEM) observations at the atomic scale.
• Analysis of crack tip zone structures and lattice reconstructions.
• Investigation of fracture toughness modifications.

Main Results:

• Identified novel fracture phenomena in 2D ReS2 not present in bulk.
• Observed lattice reconstructions at postcrack edges influencing crack tip strain.
• Demonstrated restacking of postcrack edges in shear strain-dominated cracks due to monatomic thickness.

Conclusions:

• Fracture in 2D ReS2 is governed by unique atomistic processes.
• Lattice reconstructions significantly modify fracture toughness.
• The findings offer insights for designing 2D stacking contacts with atomic precision.