Precise Drift Tracking for In Situ Transmission Electron Microscopy via a Thon-Ring Based Sample Position Measurement

Area of Science:

• Materials Science
• Catalysis
• Microscopy

Background:

• In situ transmission electron microscopy (TEM) is vital for understanding catalyst behavior during reactions.
• Temperature fluctuations during in situ experiments cause sample drift, degrading image resolution and stability.
• This drift hinders detailed observation of dynamic catalytic processes.

Purpose of the Study:

• To develop a method for tracking sample height variations during in situ TEM observations.
• To characterize the drifting behavior of different nanochips under varying thermal conditions.
• To enable precise real-time monitoring of fast catalytic reactions.

Main Methods:

• Development of a Thon-ring based sample position measurement (TSPM) technique.
• Analysis of drifting characteristics (shifting modes, expansion heights, thermal hysteresis) of commercial nanochips.
• Precise determination of gas layer thickness in a gas-cell nanoreactor using TSPM.
• Real-time tracking of nickel particle oxidation kinetics at 500°C.

Main Results:

• TSPM effectively tracks sample height variations during in situ TEM.
• Significant biases in shifting modes, expansion heights, and thermal hysteresis were observed for commercial nanochips.
• The gas layer thickness in a nanoreactor was determined to vary linearly with temperature (~8 nm/°C) and pressure (~50 nm/mbar).
• Fast oxidation kinetics of a Ni particle were successfully tracked in real-time for 12 seconds.

Conclusions:

• The TSPM method overcomes limitations of sample drift in in situ TEM.
• It allows for precise characterization of nanochip thermal behavior and gas-phase environments.
• TSPM facilitates real-time observation of fast catalytic reactions and is expected to enable automated target tracing in microscopy.