Glow Discharge Optical Emission Spectroscopy (GDOES) or optical glow discharge spectroscopy is a technique for determining chemical composition as a function of depth for film thicknesses from a few 100 nm to a few hundred micrometers. In GDOES, an Ar plasma is ignited over the surface of the sample and the material is ablated at a relatively high rate. The ablated atoms are excited and therefore emit light in the visible range, which is measured with a variety of spectrometers and the concentration of the elements is determined.
Fields of application: Routine examinations of, among others, nitriding, boriding or carburizing coatings, electroplating coatings, spray coatings, inorganic paints.
GDOES depth profile of a carbonitrided steel shows the depth distribution of carbon and nitrogen on a logarithmic depth scale.