Influence of the Laser Scanning Rate on the Structure of Rotating Lattice Single Crystal Lines

Abstract

Localized controlled heating of glass with a continuous wave laser has introduced the possibility of engineering the lattice of recently discovered rotating lattice single (RLS) crystals and thus obtaining novel metamaterials. Toward this goal, we report the role of the laser scanning speed on the lattice structure of a model system: Sb2S3 straight RLS crystal lines created in a 16SbI3–84Sb2S3 glass. The electron backscatter diffraction analysis shows that above a critical laser scanning speed the lattice rotates along the direction of scanning, the rate of lattice rotation is relatively insensitive to scanning speed, and the growth front is symmetric. In contrast, for laser scanning speeds below this critical value, the rate and direction of lattice rotation are strongly affected by the speed. Further, the growth front becomes asymmetric, which promotes the formation of new grains misoriented by ≤10°. These observations are explained in terms of the relative dominance of the temperature gradient from las...