Novel Approach to Quantitative Depth Profiling of Surfaces Using ATR/FT-IR Measurements

Abstract

Reflection theory for step-wise stratified media is applied to establish the relationship between the reflectivity data obtained from ATR/FT-IR surface depth profiling experiments and the concentration at a given surface depth. In spite of the mathematical complexity of the process, an unknown surface depth profiling can be calculated by using a linear interpolation, or by applying a function with variable parameters. Due to limited assumptions and fairly reasonable computation time, even when the sample is finely divided to achieve high spatial resolution, the linear interpolation approach seems to be particularly advantageous. The proposed methodology is tested for the distribution of surfactant molecules and calculations of the surface depth profiles in latex thin films.