In situ observation of Sb₂S₃ single crystal formation in glass by micro x-ray diffraction

Single crystal architectures in glass can be formed by a solid-solid transformation via localized heating by a laser or x-ray beam. As a result of the confined environment and the asymmetry of the boundary conditions close to the surface new phenomena such as a rotating crystal lattice are observed. This novel form of a crystals can offer new functionalities in micro/nano-opto-electro-mechanical systems. To understand the process of lattice formation that proceeds via crystal growth, we have observed in situ Sb₂S₃ crystal formation under x-ray irradiation. In these experiments, an x-ray beam is used as the heating source to fabricate the crystal structures while Laue diffraction patterns are collected at the same time. We explore the earliest stages of crystallization in this model system wherein glass transforms into single crystal without any change in local composition or long-range diffusion. The implications of these observations for the origin of the lattice rotation and crystal growth in a confined medium will be discussed.