Controllable Residual Stress Modulation and Homogenization of Diamond through HPHT Annealing

By combining optical properties characterization, systematically analyzed evolutions of optical homogeneity, residual stress and point defects, with dislocation slip activation further interpreted by the Schmid critical resolved shear stress (CRSS) criterion. The results demonstrate that increasing annealing temperature optimizes stress distribution uniformity of (110) planes by reducing the Peierls barrier and CRSS to activate dominant {111}⟨110⟩ slip systems for dislocation glide.

Dislocation-driven plastic deformation homogenizes native irregular residual stress on (110) surfaces and introduces extra uniform internal stress, while annealing at 2000 °C under 5 GPa for 120 minutes produces homogeneous residual stress over 1.5 GPa. This work offers a new route for stress engineering of high-performance diamond optics.