Cluster formation and laser-induced effects in the ablation of 2Cu(CO3)center dot Cu(OH)(2). Time-of-flight mass spectrometric study

The mechanism of laser ablation of 2Cu(CO3)·Cu(OH)2 at 308 nm is investigated by time-of-flight mass spectroscopy at laser fluences in the range of 0.07 to 0.6 J cm-2. The neutral and ion composition of the plume reveals the presence of Cu, Cu2O, CuO, H2O and CO2, which appear as free species or forming clusters. Plume composition is compatible with a thermal ablation mechanism which involves chemical processes similar to those reported for the purely thermal decomposition of the target. Velocity distributions of neutral species in the plume are measured and fitted to shifted Maxwell–Boltzmann time distributions; the best fitting yields flow velocities of 0.07 cm μs-1 for CO2 and Cu and 0.04 cm μs-1 for Cu2, which is compatible with an expansion regime characterized by weak interaction of the ejected particles.Financial support has been provided by Spanish DGI, MCyT (BQU2000-1163-C02-01). R.T. and M.J. thank C.S.I.C. for student fellowships. Contribution from CORESAL (Madrid) to R.T. fellowship is also acknowledged