Characterization of surface and subsurface defects induced by abrasive machining of optical crystals using grazing incidence X-ray diffraction and molecular dynamics

Abstract

The subsurface defects of CaF₂ single crystals induced by abrasive machining, and the influence of micro cracks on lattice structures can be evaluated by molecular dynamics simulation. The simulation results revealed the mappings between the micro cracks and diffraction pattern curve, which demonstrated that a phenomenon of "peak drift" occurred near the diffraction angle of a specific crystal plane. This work provided a novel technology for the nondestructive testing of defects of single crystal materials at nano- and micro- scales.