Liquid thickness estimation in transmission electron microscopy

Area of Science:

• Materials Science
• Nanotechnology
• Analytical Chemistry

Background:

• Transmission electron microscopy (TEM) is crucial for studying nano-scale materials in liquid environments.
• Accurate measurement and control of liquid thickness are vital for TEM imaging resolution and contrast.
• The log-ratio method in electron energy-loss spectroscopy (EELS) is limited for thicker liquid layers (log-ratio > 4).

Purpose of the Study:

• To develop an alternative method for measuring thicker liquid layers in TEM.
• To improve the characterization of nano-scale materials under liquid exposure.
• To address limitations of existing EELS thickness measurement techniques.

Main Methods:

• Utilized the energy position of the multiple scattering peak in EELS for thickness measurement.
• Applied the method under both broad-beam and focused-beam illumination conditions.
• Investigated sample holder effects on liquid thickness.

Main Results:

• The multiple scattering peak position in EELS provides a reliable measure for thicker liquid layers.
• Identified silicon chip bulging as an additional source of liquid thickness variation.
• Demonstrated methods to mitigate unwanted bulging effects in liquid holders.

Conclusions:

• The calibrated multiple scattering peak in EELS offers a robust alternative for liquid thickness measurement.
• Understanding and controlling sample holder-induced bulging is essential for accurate TEM analysis.
• This work enhances the capability of time-resolved TEM for nano-materials in liquids.