Surface stoichiometry of manganin coatings prepared by pulsed laser deposition as described by laser-induced breakdown spectrometry

Abstract

The use of laser-induced breakdown spectrometry (LIBS) for the multielemental distribution of coating samples is discussed. Surface characterization was performed by monitoring plasma emission generated by a Q-switched Nd:YAG laser operating on the second harmonic wavelength at 532 nm. Samples analyzed by LIBS consisted of manganin coatings (Cu, Ni, and Mn) prepared on Si by pulsed laser deposition from a solid manganin target (Cu 86%, Ni 2%, Mn 12%). The thickness of the coating was ∼50 nm. To improve both surface sensitivity and spectral detection, the laser beam was focused 5 mm above the sample surface. A total area of 5.6 mm × 3.5 mm was sampled with a lateral resolution of 375 μm. For quantitative purposes, the data from the coated sample were compared with those obtained from a manganin standard. Significant differences in the stoichiometry of coatings as compared with the original sample were observed.