The structure, formation, and growth dynamics of the lattice of single crystal in glass

Local heating by laser irradiation has been demonstrated as a versatile method for fabricating single crystal architectures with microscale precision. The crystal lattice can be further engineered with intrinsic stresses and systemic lattice deformations due to the unique growth surrounded by glass. The ability to locally functionalize the glass with a crystal lattice engineered across several length scales make these materials particularly desirable for optical photonic, and quantum applications. In model Sb2S3 crystal formed in Sb-S-I glasses, formation of unpaired edge dislocations leads to growth of rotating lattice single (RLS) crystal. Despite the mechanistic understanding of systemic deformation, lattice curvature and orientation could not be predicted due to unknown crystallographic dependencies and orientation stochasticity during initial crystal formation. In this work, we address these concerns by expanding the dislocation-model to fully characterize lattice curvature and further develop techniques to investigate glass structure and lattice dynamics in situ during and before crystal formation.Using a new methodology, we fully characterize lattice curvature during initial and extended crystal growth. During the former, lattice curvature and dislocation density are maximized when growing in the same direction as predominant �[100] edge dislocation Burgers vector. Furthermore, we identify and characterize secondary lattice curvature components superimposed on the typical RLS crystal lattice curvature. These secondary components align the lattice over extended crystal growth towards preferred axes of rotation (i.e., <010> or <001>), which coincide with the predominant dislocation core directions. During and after alignment, persistent RLS crystal growth forms macroperiodic structures of lattice orientation, repeating every 20 � 140 �m. This periodicity extends throughout the lattice curvature, dislocation density and arrangement, and crystal depth. In the absence of other factors, the new macroperiodic growth is stable and may have unexplored potential applications. Crystal growth and formation were studied with complimentary time-resolved in situ electron and x-ray diffraction. Single crystal formation was extended to electron heating, where the alternative absorption mechanism of electrons allowed for expanded crystal morphological control and fabrication of nanoscale (~50 nm) single crystal architectures. Laser crystallization was further extended with an in situ energy-tunable monochromatic x-ray probe. Using in situ diffraction under both radiation sources, we demonstrate development of lattice curvature under scanning beam, and rigid body lattice rotation (~3�) during the first 5 � 10 s of lattice formation under static beam. Furthermore, a novel methodology was developed for acquiring time-resolved micro-extended x-ray absorption fine structure data to probe glass structure evolution preceding crystal formation under laser irradiation. From potential glass structural changes predicting lattice development through extended crystal growth and the development of macroperiodic RLS crystal structures, a timeline of observed phenomena responsible for lattice dynamics and curvature of single crystal in glass is presented as a tool to guide future fabrication processes.