Nanodisks Synthesized By Laser-induced Phase Separation

In this thesis, a new route towards the synthesis of nanodisks was developed by combining the pulse-laser ablation in liquid with phase separation. Silicon nanodisks and silicon carbide nanodisks were synthesized and the formation mechanism of the nanodisks was investigated. The mian conclusions are as below:(1) Silicon nanodisks were synthesized by pulsed laser irradiating the suspension of SiO powders in de-ionized water with magnetic stirring. The phase separation process of SiO under the extreme non-equilibrium conditions was investigated.(2) A series of control experiments were conducted by varying liquid medium, laser pulse width, irradiation time and silicon-containning starting materials, a rapid thermal treatment of SiO powders was also performed, all of experimental results lend the support to a mechanism of solid state phase transformation in the low tempreture zone induced by laser radiation.(3) SiC nanodisks were synthesized by pulsed-laser irradiating the suspension of the amorphous SiOC powders in de-ionized water with magnetic stirring. It was proved that the extreme non-equilibrium conditions created by pulse laser can be expanded to the synthesis of other nanodisks by phase separation.