Details

Autor(en) / Beteiligte

• Yang, Ding-Shyue
• Mohammed, Omar F
• Zewail, Ahmed H

Titel

Scanning ultrafast electron microscopy

Ist Teil von

• Proceedings of the National Academy of Sciences - PNAS, 2010-08, Vol.107 (34), p.14993-14998

Ort / Verlag

United States: National Academy of Sciences

Erscheinungsjahr

2010

Quelle

MEDLINE

Beschreibungen/Notizen

• Progress has been made in the development of four-dimensional ultrafast electron microscopy, which enables space-time imaging of structural dynamics in the condensed phase. In ultrafast electron microscopy, the electrons are accelerated, typically to 200 keV, and the microscope operates in the transmission mode. Here, we report the development of scanning ultrafast electron microscopy using a field-emission-source configuration. Scanning of pulses is made in the single-electron mode, for which the pulse contains at most one or a few electrons, thus achieving imaging without the space-charge effect between electrons, and still in ten(s) of seconds. For imaging, the secondary electrons from surface structures are detected, as demonstrated here for material surfaces and biological specimens. By recording backscattered electrons, diffraction patterns from single crystals were also obtained. Scanning pulsed-electron microscopy with the acquired spatiotemporal resolutions, and its efficient heat-dissipation feature, is now poised to provide in situ 4D imaging and with environmental capability.