title: 4D electron imaging: principles and perspectives.
abstract: In this perspective we highlight developments and concepts in the field of 4D electron imaging. With spatial and temporal resolutions reaching the picometer and femtosecond, respectively, the field is now embracing ultrafast electron diffraction, crystallography and microscopy. Here, we overview the principles involved in the direct visualization of structural dynamics with applications in chemistry, materials science and biology. The examples include the studies of complex isolated chemical reactions, phase transitions and cellular structures. We conclude with an outlook on the potential of the approach and with some questions that may define new frontiers of research.
authors.affiliation: Physical Biology Center for Ultrafast Science and Technology, Arthur Amos Noyes Laboratory for Chemical Physics, California Institute of Technology, Pasadena, CA 91125, USA.
authors.forename: Dmitry
authors.initials: D
authors.lastname: Shorokhov
authors.forename: Ahmed H
authors.initials: AH
authors.lastname: Zewail
mesh_terms: D000818:Animals; D003461:Crystallography; D007422:Intestines / Q000648:ultrastructure; D008854:Microscopy, Electron / Q000295:instrumentation / Q000379:methods*; D046529:Microscopy, Electron, Transmission / Q000295:instrumentation / Q000379:methods*; D008956:Models, Chemical; D015394:Molecular Structure; D010316:Particle Size; D044367:Phase Transition; D013997:Time Factors