Deposition of nanostructured Cr O on amorphous substrates 2 3 under laser irradiation of the solid–liquid interface

The deposition of epitaxial films of Cr2O3, Fe2O3, and MnO2 under laser irradiation of the interface sapphire-absorbing liquid has been reported recently. In similar experimental conditions, laser irradiation of the amorphous solid–liquid interface results in deposition of a polycrystalline film. In the present paper, the deposition of Cr2O3 on a glass substrate induced by radiation of a Cu vapor laser is studied. Irradiation of the interface glass–aqueous solution of CrO3 at fluence of 2–5 Jrcm2 at ls510.6 nm results in the deposition of Cr2O3 which consists of oriented nanoclusters with size of 8–20 nm. The subsequent chemical etching of the glass results in a free-standing film of Cr2O3 with lateral dimensions of several mm2 and 30–50 mm thick. The mathematical model of the deposition process is considered based on the semi-analytical solution of the non-stationary heat diffusion equation for a gaussian profile of laser beam. It is shown that during a ns laser pulse the maximum of the temperature shifts from the interface towards the absorbing liquid. The results of calculations are qualitatively consistent with experimental data on the dependence of the thickness of Cr2O3 deposit on the heat diffusion coefficient of a solid substrate. q1999 Elsevier Science B.V. All rights reserved