Advances and Discoveries in Non-equilibrium Driven Nanomaterials and Thin Films: On-Demand Poster Session
Sponsored by: TMS Functional Materials Division, TMS: Advanced Characterization, Testing, and Simulation Committee, TMS: Thin Films and Interfaces Committee
Program Organizers: Ritesh Sachan, Oklahoma State University; Amit Pandey, Lockheed Martin Space; Saurabh Puri, Microstructure Engineering; Amber Srivastava, Indian Institute of Technology; Nuggehalli Ravindra, New Jersey Institute of Technology

Monday 8:00 AM
March 14, 2022
Room: Nanostructured Materials
Location: On-Demand Poster Hall

Laser Irradiation Induced Nanoscale Surface Transformations in Strontium Titanate: Ashish Kumar Gupta1; Siddharth Gupta2; Soumya Mandal1; Jagdish Narayan2; Ritesh Sachan1; 1Oklahoma State University; 2North Carolina State University
    Understanding the atomic rearrangements and structural transformations in SrTiO3 via nanosecond pulsed-laser irradiation-induced melting and ultrafast quenching is a challenge. Using scanning transmission electron microscopy, we observe that laser-irradiated surfaces in single crystalline SrTiO3 transform into an amorphous phase with an interposing disordered crystalline region between the phases. The formation of disordered phase attributes to rapid recrystallization of SrTiO3 from the melted phase, which is constrained by an epitaxial relation with the pristine region. By mapping lattice distortions with atomic-resolution images, we estimate ~4-5% lattice disorder in the disordered region compared to the pristine lattice. Disorder increases upto ~15% towards the surface and transforms to an amorphous phase. We further confirm the transformation of Ti+4 to Ti+3 in the disordered region due to oxygen vacancy formation. Overall, the study of atomic rearrangement in laser irradiated SrTiO3 enables the understanding of correlated electronic, optical, and magnetic properties.