Nanometric range depth-resolved analysis of coated-steels using laser-induced breakdown spectrometry with a 308 nm collimated beam

Abstract

The spatial profile from an XeCl excimer laser was modified using a simple two-lenses telescope to generate a flat energy-profile beam that impinged a layered sample (a Zn-coated steel) without beam conditioning. The irradiance obtained (about 107 W cm–2) was high enough to vaporize the target, to cause plasma formation and to allow atomic emission spectrometry with acceptable signal-to-noise ratio. Modification in beam energy distribution resulted in flat ablated profiles and improved depth-resolution up to the few nm pulse–1 range was attained. The net intensity areas were transformed into normalized values leading to plots in excellent agreement with those provided by commercial depth-resolved analysis instruments.