Dependence of LIBS spectra on the surface composition and morphology of W/Al coatings

•The study is a step of LIBS application for the quantitative estimation of the fuel retention at ITER walls.•Besides LIBS, samples with ITER-relevant coatings were characterized by SEM, XRD and SIMS techniques.•Depending on micro-and nanoscale properties of samples the ablation rate of samples with mono-component coatings could differ by an order of magnitude.•The total emission of the ablated material is related to the surface morphology.•Due to the ablation non-stoichiometry of Al/W coatings (Al is proxy for beryllium), Al and W depth profiles differ remarkably.