RF Glow Discharge Optical Emission Spectrometry provides direct measurement of the chemical composition of thin and thick layers as a function of depth with excellent resolution.
The technique relies on the sputtering of a representative area of the material of interest (conductive or not) by a high density (1014) and low energy plasma making it a very valuable tool for corrosion studies as multiple publications have shown.
The unique characteristics of the GD plasma allow very fast erosion (typically 2-10nm/s - several microns per minute) with minimum surface damage (as the incident particles have an average energy of about 50eV). Patented developments have also permitted to quickly sputter thick polymer layers allowing corrosion studies of embedded layers to be performed as for car bodies. The instrument is also used advantageously for sample preparation in SEM.
The capability to simultaneously measure all elements of interest (including H – even D Deuterium, O, C, Cl, F etc and the speed of analysis help to understand the corrosion mechanisms or validate protection coatings.