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Published May 25, 2011 | public
Journal Article

4D Scanning Ultrafast Electron Microscopy: Visualization of Materials Surface Dynamics


The continuous electron beam of conventional scanning electron microscopes (SEM) limits the temporal resolution required for the study of ultrafast dynamics of materials surfaces. Here, we report the development of scanning ultrafast electron microscopy (S-UEM) as a time-resolved method with resolutions in both space and time. The approach is demonstrated in the investigation of the dynamics of semiconducting and metallic materials visualized using secondary-electron images and backscattering electron diffraction patterns. For probing, the electron packet was photogenerated from the sharp field-emitter tip of the microscope with a very low number of electrons in order to suppress space–charge repulsion between electrons and reach the ultrashort temporal resolution, an improvement of orders of magnitude when compared to the traditional beam-blanking method. Moreover, the spatial resolution of SEM is maintained, thus enabling spatiotemporal visualization of surface dynamics following the initiation of change by femtosecond heating or excitation. We discuss capabilities and potential applications of S-UEM in materials and biological science.

Additional Information

© 2011 American Chemical Society. Published In Issue May 25, 2011; Article ASAP May 03, 2011; Received: April 05, 2011. This work was supported by the NSF and the Air Force Office of Scientific Research in the Gordon & Betty Moore Physical Biology Center at Caltech. O.F.M. is grateful for a distinguished scholar award provided by the Arab Fund for Economic and Social Development. S.K.P. thanks Prof. Zewail for generous hospitality during the sabbatical stay.

Additional details

August 19, 2023
October 23, 2023