MSE Seminar: “Deciphering the Structure and Properties of Amorphous Functional Materials using 4D-STEM”

Date(s) - 02/06/2024
3:00 pm - 4:00 pm

Rhines Hall 125



Understanding amorphous materials is not only a fundamental problem but also a practical one, since controlling the flexible nature of the atomic configuration in amorphous materials can potentially lead to novel properties that are not achievable in crystalline materials. However, understanding amorphous materials remains formidably challenging due to the lack of long-range atomic ordering. Instead, recent works have revealed that the atomic ordering at certain length scales, namely short-range ordering and medium range-ordering (MRO) may be the key to understanding the properties of these materials.

Fluctuation electron microscopy (FEM) has been an effective way to understand the MRO and how it attributes to the structural fluctuation in amorphous materials. In recent years, significant advances have been made in FEM by the introduction of the pixelated STEM detectors. This led to a deeper understanding of the structure of amorphous materials by enabling the full 4-dimensional (4D) acquisition of scanning nanodiffraction patterns, which provides statistically significant information about how MRO forms and influences their important properties critical to their applications.

This presentation will show the amorphous structure-property relationships that we recently established using 4D-STEM, such as in metallic glasses, ALD amorphous oxide thin films, and chalcogenides with novel physical phenomena.


Jinwoo Hwang, Ph.D.

Associate Professor, Department of Materials Science & Engineering
Ohio State University

Dr. 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 the thermal properties of materials and interfaces.