A (S)TEM gas cell holder with localized laser heating for in situ experiments

Area of Science:

• Materials Science
• Nanotechnology
• Physical Chemistry

Background:

• Aberration correction has made atomic resolution imaging in transmission electron microscopy (TEM) a standard technique.
• Observing reactions in real-time within realistic environments at atomic resolution is a key emerging area in electron microscopy.
• Current in situ TEM methods face limitations in controlling environmental conditions and maintaining atomic resolution.

Purpose of the Study:

• To introduce a novel in situ gas cell holder for transmission electron microscopy.
• To enable atomic resolution imaging of reactions under controlled gas pressures and compositions.
• To assess the performance of the gas cell holder in terms of resolution and contrast at ambient pressure.

Main Methods:

• Development and implementation of a new in situ gas cell holder compatible with various sample types.
• Integration of localized heating and precise gas pressure/composition control.
• Atomic resolution imaging experiments at ambient pressure with varying gas path lengths.

Main Results:

• Direct visualization of 0.25-nm lattice fringes in nanoparticles at ambient pressure with gas path lengths up to 20 μm.
• Quantitative analysis showing decreased contrast and resolution with increased pressure and gas path length.
• Demonstration that resolutions better than 0.2 nm are achievable at ambient pressure with gas path lengths < 15 μm.

Conclusions:

• The developed in situ gas cell holder facilitates atomic resolution imaging under realistic gas conditions.
• The system allows for the study of dynamic processes at the nanoscale in controlled environments.
• This technology opens new avenues for in situ investigations in materials science and chemistry.