Mapping and Controlling Liquid Layer Thickness in Liquid-Phase (Scanning) Transmission Electron Microscopy.

Area of Science:

• Materials Science
• Analytical Chemistry
• Nanotechnology

Background:

• Liquid-Phase Transmission Electron Microscopy (LP-TEM) is crucial for real-time nanoscale material process monitoring in liquids.
• Pressure differences in LP-TEM cause membrane bending, leading to variable liquid thickness, hindering accurate analysis and resolution.
• This variability imposes diffusion limitations, complicating the achievement of bulk solution conditions.

Purpose of the Study:

• To develop methods for quantitatively mapping liquid layer thickness in LP-TEM.
• To demonstrate dynamic control over liquid thickness within the liquid cell.
• To enable high-resolution imaging and overcome diffusion limitations in LP-TEM experiments.

Main Methods:

• Quantitative mapping of liquid layer thickness using low electron dose (<0.01 e⁻ Å⁻²).
• Dynamic modulation of liquid thickness by adjusting internal liquid cell pressure (Laplace and external pressures).
• Utilizing reproducible inward bulging of silicon nitride (SiNₓ) membranes for ultra-thin liquid layers.

Main Results:

• Accurate, low-dose quantitative mapping of liquid layer thickness is achievable for any liquid.
• Reproducible inward bulging of membranes creates an ultra-thin liquid layer in the central area for enhanced resolution.
• Dynamic alteration of liquid thickness is demonstrated, potentially overcoming diffusion limitations.

Conclusions:

• The presented methods allow precise measurement and dynamic adjustment of liquid thickness in LP-TEM.
• These advancements facilitate new experimental designs and improved control over solution chemistry in nanoscale studies.
• This work enhances the reliability and applicability of LP-TEM for in-situ nanoscale material analysis.