Ultrafast electron crystallography and nanocrystallography: for chemistry, biology and materials science. Part I. Ultrafast electron crystallography

by Schafer, Lothar; Tarasov, Yury I.; Koshelev, Aleksandr V.; Ischenko, Anatoly A.

The direct probing and understanding of the dynamics of chem. and biol. processes occurring in condensed matter, is currently in its early stages. Progress in this field has been pushed by the development of methods for the study of the structural dynamics of matter in a state far from equilibrium, including extreme states. The forthcoming information serves as the basis for testing new theor. approaches to the description of the substance in casually connected triad "structure-dynamics-function". Observation of the dynamic behavior of matter in the space-time continuum on ultrashort time scales is a necessary first step in the explanation and, ultimately, control of far from equilibrium processes, and functionality of the systems studied. The method of ultrafast electron crystallog. (UEC) makes it possible to investigate transient nonequilibrium structures, which yield decisive information about the structural dynamics of the phase transitions and coherent dynamics of the nuclei in the solid state, on the surface, and in macromol. systems. In recent years, the electron bunch path length in the UEC apparatus diminished significantly, while the accelerating voltage increased considerably. Therefore, femtosecond electron pulses were obtained. A technique of radio frequency grouping of electrons was proposed to increase the electron pulse brightness. The method of electron field emission was used to increase the spatial coherence, and ponderomotive wave front acceleration was applied to reduce the mismatch between the velocities of the light and electron pulses and to contract the electron bunches. These achievements have opened up new possibilities for studying the coherent structural dynamics - at. and mol. movie with femtosecond temporal resolution The results of several internationally renowned research groups are included and cited.

Journal
Izvestiya Vysshikh Uchebnykh Zavedenii, Khimiya i Khimicheskaya Tekhnologiya
Volume
60
Issue
5
Year
2017
Start Page
4-20
URL
https://dx.doi.org/10.6060/tcct.2017605.5608
ISBN/ISSN
2500-3070; 0579-2991
DOI
10.6060/tcct.2017605.5608