Development and applications of ultrafast transmission electron microscopy

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Ultrafast transmission electron microscopy (UTEM) is crucial for studying dynamic processes in materials.
• Advancements in detector technology and imaging techniques have expanded UTEM's capabilities.

Purpose of the Study:

• To review the development and applications of UTEM at RIKEN.
• To introduce the five-dimensional scanning TEM (5D STEM) for ultrafast nanoscale movie creation.
• To showcase recent advancements in observing dynamic phenomena in nanomaterials.

Main Methods:

• Pump-probe transmission electron microscopy (TEM) with a wide temporal range.
• Five-dimensional scanning TEM (5D STEM) combining UTEM and pixelated detectors.
• Convergent-beam electron diffraction (CBED) and differential phase contrast (DPC) imaging.
• Lorentz TEM (LTEM) for magnetic dynamics.
• Bright-field TEM and electron diffraction for photoinduced phenomena.

Main Results:

• Observed magnetic skyrmion dynamics on nanosecond-to-microsecond timescales.
• Captured photoinduced acoustic wave generation in the picosecond regime.
• Demonstrated quantitative time-dependent strain mapping with 4 ps and 8 nm accuracy using 5D STEM.
• Visualized ultrafast demagnetization with 10 ns and 400 nm resolution using DPC.

Conclusions:

• UTEM and 5D STEM provide unprecedented capabilities for ultrafast nanoscale imaging.
• These techniques allow for the detailed study of dynamic physical quantities and phenomena in nanomaterials.
• The presented results highlight the potential of UTEM for advancing materials science and condensed matter physics research.