Topic: Multiscale Spatial Characterization of Atomic Structures, Electric Fields, and Charges at Functional Material Interfaces

Presenter: Gao Wenpei

Date: Wednesday, April 2, 2025, 12:00–13:30

Location: 1st Floor Café, Building 6

Abstract

Recent studies on ferroelectric oxides reveal novel interfacial phenomena such as 2D electron gases, polarization vortices, and skyrmions. Transmission Electron Microscopy (TEM), with its high spatial resolution and spectroscopic capabilities, is vital for uncovering interfacial structures and novel physics. This talk introduces 4D scanning electron diffraction in TEM, integrating fast cameras and advanced image processing to measure electric fields, charges, and polarization across multiple spatial scales. It covers:

1.Mapping electric field and charge distribution at the atomic scale in perovskite ferroelectrics.

2.Quantifying atomic-scale dipoles and interfacial variations.

3.Revealing the evolution of polarization from atomic to microscale by adjusting electron probe sizes.

Biography

Gao Wenpei is an Associate Professor at the School of Materials Science and Engineering, Shanghai Jiao Tong University, and at the Future Materials Innovation Center, ZIAS. His group develops synthesis methods for catalysts and oxides, and advanced TEM techniques. He studies nanostructured catalyst dynamics at solid-liquid, solid-gas, and metal-substrate interfaces. Published 80+ papers in Nature, Science, Nature Nanotechnology, Nature Electronics, etc. Recipient of the Albert Crewe Award and Eric Samuel Award from the Microscopy Society of America, and supported by national and Shanghai talent programs.