MSE Seminar: Dr. Jinwoo Hwang, Ohio State University
Monday, February 19, 2024
Room 1105 (Pepco) Kim Engineering Bldg.
4D-STEM of Materials and Interfaces: Establishing Structure-Property Relationships at the Atomic Scale
Abstract: Development of new materials and advancing cutting-edge materials science often require establishing new structure-property relationships at the atomic-to-nanometer scale. We develop and utilize novel analysis methods based on 4-dimensional scanning transmission electron microscopy (4D-STEM) to uncover the details of atomic structure and defects that critically affect the important properties of materials. This presentation will highlight the important development of 4D-STEM techniques and some of the new structure-property relationships that we discovered in recent years, which includes: (i) unusual formation of point defect complexes and extended defects and their impact on the properties of ultra-wide band gap gallium oxide materials and interfaces for high-power device applications, (ii) nanoscale structural heterogeneity and medium range ordering that governs the mechanical and functional properties of metallic, oxide, and organic amorphous materials, (iii) interfacial strain at oxide interfaces that realize new magnetic behavior and switching for novel spintronics applications, and (iv) 4D-STEM based Debye-Waller thermometry that determines thermal properties of materials and interfaces at the nanometer scale.
Bio: Jinwoo Hwang is an Associate Professor in the Department of Materials Science and Engineering at the Ohio State University (OSU). His research focuses on developing new scanning transmission electron microscopy (STEM) techniques to investigate the structural origins of a wide range of important properties of materials. Current research topics include structure-property relationships in amorphous and glassy materials, defects in ultra wide band gap semiconductors, magnetic insulators for novel spintronics, and advancing 4D-STEM to investigate thermal properties of materials and interfaces.