Elastic properties of graphite moiré patterns using STM tip-induced deformation

Highly Oriented pyrolytic graphite (HoPG) is the only monoatomic crystal found to host naturally formed moiré patterns on its cleaved exfoliated surfaces which are coherent over micrometers with fixed periodicities. This is in contrast to twisted graphene layers where the moire pattern is under considerable strain and doesn't show the same long range coherence. In this work, we use STM tip-induced deformation to externally strain moiré patterns in Graphite and observe how they respond mechanically. This reveals the crystal orientation dependent elastic properties as a function of twist angles. We observe lateral stretching of domain walls (DWs) in graphite moiré which are unseen in graphene moiré. Surface deformation of formed graphitic Moiré patterns reveals the inter-layer van der Waals (vdW) strength varies across its domains.