Infrared Attenuated Total Reflection Spectroscopy for a Layered Structure

Area of Science:

• Spectroscopy
• Materials Science
• Optics

Background:

• Analyzing thin film structures requires precise optical methods.
• Infrared spectroscopy is crucial for understanding molecular interactions and material properties.

Purpose of the Study:

• To derive and validate a method for analyzing structural distribution in thin films using infrared attenuated total reflection (ATR).
• To investigate energy flow and absorption mechanisms in layered structures relevant to visible light wavelengths.

Main Methods:

• Infrared attenuated total reflection (ATR) was derived based on wave vector and Poynting vector analysis.
• The method considered the phase of transmitted light and energy flow into the rarer medium.
• A layered structure involving an alumina gel film, amorphous alumina, and a Ge prism was used for validation.

Main Results:

• The derived ATR method successfully analyzed structural distribution in thin films.
• Absorption was accurately attributed to energy flow into the rarer medium.
• Validation was achieved by observing three characteristic absorption bands of ethyl acetoacetate (EAcAc) in the alumina gel film.

Conclusions:

• The derived infrared ATR method provides a robust approach for structural analysis of thin films.
• The study demonstrates the importance of Poynting vector components in understanding optical absorption in layered materials.
• This technique is valuable for characterizing materials with thicknesses comparable to visible light wavelengths.