Effects of the interacting defects composed of intrinsic stacking faults and inversion domain boundaries on the mechanical property of w-BN phase

Wurtzite Boron Nitride ( w -BN) is highly promising for advanced electronics due to superhardness, wide bandgap, and high thermal conductivity. And the intrinsic defects play a critical role in affecting the thermal stability and mechanical properties. This study investigates the cohesive energy and mechanical properties of w -BN with intrinsic stacking faults (ISFs) and inversion domain boundaries (IDBs) using the combination of first principles calculations and molecular dynamics simulations. The results show that IDBs effectively slow down dislocation nucleations and propagations. Meanwhile, ISFs do not inhibit initial nucleations of dislocation during the indentation but significantly impede their propagations at the greater depths by as acting as barriers. The effect of ISFs and IDBs concentrations indicates that IDBs-28/1/3 and ISFs-3/1/17 are effective in delaying dislocation evolution. Finally, the three-dimensional defective networks constructed by ISFs and IDBs demonstrate the enhanced inhibition of dislocation nucleation and propagation of dislocations. The results pass the way to understand the effect of intrinsic defects in covalent compounds.