Depth-profiling and diffusion measurements in ice films using infrared laser resonant desorption

Area of Science:

• Materials Science
• Physical Chemistry
• Spectroscopy

Background:

• Understanding diffusion and composition in ice is crucial for various scientific fields.
• Existing techniques for ice analysis may lack the required depth resolution or sensitivity.
• Infrared laser-based methods offer potential for non-destructive, high-resolution analysis.

Purpose of the Study:

• To develop and validate a new infrared laser resonant desorption (LRD) technique for depth-profiling and diffusion measurements in ice.
• To assess the capabilities of LRD for analyzing ice films with submicrometer spatial resolution.
• To demonstrate the application of LRD for monitoring diffusion processes in ice.

Main Methods:

• Utilized an Er:YAG laser (lambda = 2.94 microm) for resonant desorption of H2O molecules from ice.
• Developed control experiments on pure and isotopically mixed ice films to optimize LRD parameters.
• Applied LRD depth-profiling to analyze H2 18O/H2 16O multilayers and ice/HCl/ice sandwich structures.
• Investigated Na diffusion into ice using LRD after controlled Na adsorption.

Main Results:

• The LRD technique demonstrated depth-profiling capabilities with submicrometer spatial resolution and high sensitivity.
• Desorption depth was controllable and could be tailored relative to the optical penetration depth.
• LRD successfully analyzed isotopic multilayers and monitored HCl hydrate and Na diffusion in ice over time.

Conclusions:

• The developed infrared laser resonant desorption (LRD) technique is a powerful tool for depth-profiling and diffusion studies in ice.
• LRD provides high spatial resolution and sensitivity, enabling detailed analysis of ice film structures.
• This technique opens new avenues for investigating dynamic processes within ice matrices.