LASER-INDUCED DEPOSITION OF COPPER AND LEAD POWDERS

Copper and lead powders were precipitated by laser-induced reduction of copper(II) formate, copper(II) acetate, and lead(II) acetate dispersed/dissolved in glycerine by exposure to 248 nm KrF pulsed laser radiation. The deposited powders consisted of pure copper and a mixture of pure lead and partially reduced metallo-organic complexes, respectively. The reduction of the metallo-organic complex of lead was completed thermally. Temperature, concentration, laser pulse repetition rate, and stirring influenced the deposition rate in both cases. The copper particles were predominantly hexagonal in shape and ranged in size from 0.01-0.04-mu-m. The lead particles were football shaped and had a very narrow size distribution, with an axial dimension of about 0.5-mu-m. It was shown from a spectroscopic analysis of the reaction products that the initial nucleation was caused by photochemical processes. However, exposure of the nonaqueous solutions to CO2 laser pulses at room temperature did not yield any particles.