Student: Evan Musterman
Project: Lattice Rotation in laser-fabricated single crystals in glass: its origin and implications for lattice engineering
View: Research Poster (PDF) | Presentation (YouTube)
Department: Materials Science and Engineering
Advisor: Himanshu Jain
Abstract
Laser heating of a glass surface can be used to fabricate single crystal architecture that exhibit a characteristic lattice rotation. These rotating lattice single (RLS) crystals rotate about an axis parallel to the glass surface and perpendicular to the growth direction. This type of controlled crystal growth can be used to produce lattice engineered metamaterials with potential applications in photonic and optical devices. A dislocation-based mechanism was hypothesized for this rotation based on μXRD results. We validate this hypothesis by direction observation and characterization of these dislocations via transmission electron microscopy (TEM) in Sb2S3 crystal lines fabricated in Sb-S-I glass as a model system. We demonstrate that rotation rates measured by electron diffraction agree with those calculated by the observed dislocation densities and Burgers vectors. Using the dislocation-based mechanism, we go on to show how the rotation rate depends on the direction of crystal growth with a maximum in the direction of the largest dislocation. These results provide direct proof of the dislocation mechanism for lattice rotation in RLS crystals, and very likely other forms of growth actuated lattice bending, twisting and non-crystallographic branching seen in spherulites and other unique forms of crystal growth in nature.
About Evan Musterman
Evan Musterman is a third year Ph.D. student in Materials Science and Engineering at Lehigh University researching laser-fabrication of single crystals architectures in glass. He received his B.S. in Ceramic Engineering from the Missouri University of Science and Technology in May 2018 and M.S. in Materials Science and Engineering from Lehigh University in January 2021. At Lehigh, Evan is advised by Dr. Himanshu Jain and co-advised by Dr. Volkmar Dierolf. His graduate research focuses on laser-fabrication of Sb2S3 crystals on the surface of Sb-S-I glasses, with particular interest on the growth-actuated lattice rotation observed in these surface crystals.