Flexural phonon instability defines intrinsic van der Waals elastic limits in the interlayer direction.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 42270645.
- Also identified by DOI 10.1038/s41467-026-74353-w.
- No licence information is recorded for this record.
- Because redistribution is not established, this page shows the abstract only. Follow the links below for the full text.
Abstract
Frenkel's cohesive model predicts an ideal elastic strain limit of ~10% for strong solids, a bound upheld in conventional materials. We demonstrate that such consistency breaks down in van der Waals (vdW) solids, challenging established strength theories. In situ tensile tests, combined with first-principles calculations, reveal unexpected localized decohesion failure at only ~3% strain in graphite and ~2% in h-BN along the interlayer direction-well below defect-controlled limits-defining their intrinsic elastic limits. This localization phenomenon is absent in MoS<sub>2</sub>, GaSe, and 3D crystals. We identify flexural phonon instability as the trigger for a cascade of strain localization, creating periodic nanogaps to release elastic strain energy. This dynamic instability redefines the intrinsic elastic limits of vdW crystals and opens pathways to tailor their structural/transport properties via strain engineering.