Production of nanosized zirconia particles by pulsed CO2 laser evaporation

In this article we report on the production of nanosized zirconia particles by CO2 laser evaporation. The radiation source was a transverse flow CO2 laser operating in the continuous or the pulsed mode. Pulses between 1 and 500 mu s duration could be generated by two different Q-switching techniques. The evaporation rates as well as the diameter of the particles and their density distributions were investigated with regard to their dependence on the laser power, the pulse shape, and the properties of the carrier gas. By means of simple models the experimental results could be interpreted. Furthermore a kinetic rate equation has been derived for the formation and growth of small particles. Good agreement is found between the experiments and this theory. (C) 1999 Laser Institute of America.