Jm. Vadillo et Jj. Laserna, DEPTH-RESOLVED ANALYSIS OF MULTILAYERED SAMPLES BY LASER-INDUCED BREAKDOWN SPECTROMETRY, Journal of analytical atomic spectrometry, 12(8), 1997, pp. 859-862
The capability of laser-induced breakdown spectrometry (LIES) to resol
ve complex depth profiles is demonstrated. Electrolytically deposited
brass samples were analyzed by monitoring the emission corresponding t
o Cr (357.8 nm), Ni (341.4 nm), Cu (327.4 nm) and Zn (334.5 nm). The n
ominal thickness of the layers was known, which permitted an estimate
of the ablated mass in the range between 150 and 500 nm per pulse depe
nding on the matrix and laser irradiance. Laser irradiance was varied
by defocusing, and its effect on the depth-resolution of LIES was test
ed For comparison purposes, a commercial zinc-coated steel was also st
udied by following the Zn and Fe emission intensity depth profiles wit
h a commercial glow-discharge optical emission spectrometry system to
obtain information on the exact location of the Zn-Fe interface (12 mu
m). The ablation rate in terms of ablated mass per pulse was found to
be at the ng per pulse level and depended on the laser pulse irradian
ce.