Practical considerations for high spatial and temporal resolution dynamic transmission electron microscopy

Armstrong, Michael R.; Boyden, Ken; Browning, Nigel D.; Campbell, Geoffrey H.; Colvin, J. D.; DeHope, W.J.; Frank, Alan; Gibson, D. J.; Hartemann, F. V.; Kim, Judy; King, Wayne E.; LaGrange, Thomas; Pyke, BJ; Reed, Bryan W.; Shuttlesworth, R.; Stuart, B. C.; Torralva, Ben

doi:10.1016/j.ultramic.2006.09.005

Cited by 102 publications

(64 citation statements)

References 47 publications

(48 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, they have limited penetrating power and struggle to obtain high-quality single-shot images due to space-charge issues 7 . Synchrotron beams from third-generation sources have comparatively long pulse lengths of 10-100 ps, as determined by the shortest electron bunch length possible in a given storage ring.…”

mentioning

confidence: 99%

Ultrafast single-shot diffraction imaging of nanoscale dynamics

et al. 2008

View full text Add to dashboard Cite

The transient nanoscale dynamics of materials on femtosecond to picosecond timescales is of great interest in the study of condensed phase dynamics such as crack formation, phase separation and nucleation, and rapid fluctuations in the liquid state or in biologically relevant environments. The ability to take images in a single shot is the key to studying non-repetitive behaviour mechanisms, a capability that is of great importance in many of these problems. Using coherent diffraction imaging with femtosecond X-ray free-electron-laser pulses we capture time-series snapshots of a solid as it evolves on the ultrafast timescale. Artificial structures imprinted on a Si 3 N 4 window are excited with an optical laser and undergo laser ablation, which is imaged with a spatial resolution of 50 nm and a temporal resolution of 10 ps. By using the shortest available free-electronlaser wavelengths 1 and proven synchronization methods 2 this technique could be extended to spatial resolutions of a few nanometres and temporal resolutions of a few tens of femtoseconds. This experiment opens the door to a new regime of time-resolved experiments in mesoscopic dynamics.To date, optical pulses have made it possible to resolve dynamics on the femtosecond timescale, but the spatial resolution of these studies has been limited to a few micrometres 3 . On the other hand, femtosecond X-ray pulses have been used to detect Å ngstrom-scale atomic motions in extended crystalline materials with long-range order through time-resolved diffraction experiments 4,5 . An entirely different methodology is needed to investigate the ultrafast dynamics of non-crystalline materials at nanometre length scales. Applications at these scales can be found in the study of fracture dynamics, shock formation, spallation, ablation, and plasma formation under extreme conditions. In the solid state it is desirable to directly image dynamic processes such as nucleation and phase growth, phase fluctuations and various forms of electronic or magnetic segregation.Electron microscopes can provide nanometre to atomic resolution, and have recently been demonstrated with ultrafast pulses 6 . However, they have limited penetrating power and struggle to obtain high-quality single-shot images due to space-charge issues 7 . Synchrotron beams from third-generation sources have comparatively long pulse lengths of 10-100 ps, as determined by the shortest electron bunch length possible in a given storage ring. Synchrotron sources can produce short-pulse ($100 fs) X-rays when operated as femtosecond slicing sources 8 , but produce comparatively weak X-ray beams of 1 Â 10 7 photons per second. Along with X-ray pulses from femtosecond laser plasma sources 9,10 and high-harmonic-generation sources 11 this limits their use to non-destructive phenomena where weak signals can be accumulated over many repeatable excitations of the sample.The intense femtosecond X-ray pulses from free-electron-laser (FEL) sources provide the penetrating power, spatial resolution and single-shot imaging c...

show abstract

mentioning

confidence: 99%

Ultrafast single-shot diffraction imaging of nanoscale dynamics

et al. 2008

View full text Add to dashboard Cite

show abstract

“…If such instruments are operated at high charge densities (single-shot mode), the evaluation of the spatial and temporal resolution has to account for the space-charge effect each time the electrons come in close proximity to each other both prior and after scattering by the specimen. 28 From these studies, we now address the experimental regimes of this laboratory. For single-electron UEM, it is clear that two effects have been suppressed by this development, namely the severe influence of space-charge not only on the temporal (longitudinal) broadening, but also on the spatial (lateral) dispersion, which introduces divergence and, hence, a loss in image resolution.…”

Section: Discussionmentioning

confidence: 99%

Ultrashort electron pulses for diffraction, crystallography and microscopy: theoretical and experimental resolutions

Gahlmann

Park

Zewail

2008

Phys. Chem. Chem. Phys.

120

125

View full text Add to dashboard Cite

Pulsed electron beams allow for the direct atomic-scale observation of structures with femtosecond to picosecond temporal resolution in a variety of fields ranging from materials science to chemistry and biology, and from the condensed phase to the gas phase. Motivated by recent developments in ultrafast electron diffraction and imaging techniques, we present here a comprehensive account of the fundamental processes involved in electron pulse propagation, and make comparisons with experimental results. The electron pulse, as an ensemble of charged particles, travels under the influence of the space-charge effect and the spread of the momenta among its electrons. The shape and size, as well as the trajectories of the individual electrons, may be altered. The resulting implications on the spatiotemporal resolution capabilities are discussed both for the N-electron pulse and for single-electron coherent packets introduced for microscopy without space-charge.

show abstract

“…The approach taken with the dynamic transmission electron microscope (DTEM) is to integrate high performance pulsed lasers with the microscope electron optical column [33]. Two pulsed lasers are required, one for electron pulse generation and one for specimen drive.…”

Section: Methodsmentioning

confidence: 99%

Quantifying transient states in materials with the dynamic transmission electron microscope

Campbell

LaGrange

Kim

et al. 2010

Journal of Electron Microscopy

View full text Add to dashboard Cite

(250 words)The Dynamic Transmission Electron Microscope (DTEM) offers a means of capturing rapid evolution in a specimen through in-situ microscopy experiments by allowing 15 ns electron micrograph exposure times. The rapid exposure time is enabled by creating a burst of electrons at the emitter by ultraviolet pulsed laser illumination. This burst arrives a specified time after a second laser initiates the specimen reaction. The timing of the two Q-switched lasers is controlled by highspeed pulse generators with a timing error much less than the pulse duration. Both diffraction and imaging experiments can be performed, just as in a conventional TEM. The brightness of the emitter and the total current control the spatial and temporal resolutions. We have demonstrated 7 nm spatial resolution in single 15 ns pulsed images. These single-pulse imaging experiments have been used to study martensitic transformations, nucleation and crystallization of an amorphous metal, and rapid chemical reactions. Measurements have been performed on these systems that are possible by no other experimental approaches currently available.2

show abstract

Practical considerations for high spatial and temporal resolution dynamic transmission electron microscopy

Cited by 102 publications

References 47 publications

Ultrafast single-shot diffraction imaging of nanoscale dynamics

Ultrafast single-shot diffraction imaging of nanoscale dynamics

Ultrashort electron pulses for diffraction, crystallography and microscopy: theoretical and experimental resolutions

Quantifying transient states in materials with the dynamic transmission electron microscope

Contact Info

Product

Resources

About