SEMINAR 2024
Probing Materials Synthesis and Dynamics with Advanced Electron Microscopy
| Speaker | Guomin Zhu, University of California, Santa Barbara |
| Date/Time | Wednesday, 23 Oct, 11AM |
| Registration link | https://nus-sg.zoom.us/meeting/register/tZAvcOuprjkqG9UsJT2xGrIzGuvbskGc7YGw#/registration |
| Host | A/Prof Utkur Mirziyodovich Mirsaidov |
Abstract
Numerous lines of evidence are challenging the traditional picture of crystallization by atomic attachment. Several alternative crystallization pathways involving particle attachment are proposed. The nuances of these crystallization pathways make it very challenging to elucidate the crystallization pathway[1].
In this talk, I will present my work on the elucidation of the crystallization mechanism for hematite mesocrystals, a class of hierarchical materials composed of crystallographically aligned nanocrystals as building blocks using in situ liquid phase transmission electron microscopy (TEM). I discovered a novel pathway of surface-induced nucleation and aggregation, which is changing paradigms for the growth of those hierarchical materials and how nucleation occurs at the solid/liquid interface[2]. I further applied this technique to uncover the dissolution dynamics of hematite. A previously unknown dissolution pathway which involves necking and particle detachment is uncovered[3]. Finally, I will present the study of lithium nucleation and growth in lithium metal batteries by developing and applying cryogenic TEM techniques.
Reference:
[1] Science 349.6247 (2015): aaa6760.
[2] Nature 590.7846 (2021): 416-422.
[3] Nature Communications 14.1 (2023): 6300.
Biography
Dr. Guomin Zhu is currently a Postdoctoral Associate in the Materials Department at the University of California, Santa Barbara (UCSB), where he works with Prof. Susanne Stemmer. His broad research interest lies in studying dynamics of materials transformation (e.g., nucleation and growth, phase transformation, order characterization) for materials synthesis, energy conversion and storage, and quantum materials by developing and applying advanced electron microscopy tools and methods (e.g., in situ liquid cell electron microscopy, cryogenic electron microscopy, 4D-STEM).
Guomin received his Ph.D. in Materials Science and Engineering in 2020 from the Univeristy of Washington, under the supervision of Prof. James De Yoreo. He was a research fellow at Pacific Northwest National Laboratory (PNNL) from 2018 to 2020.
