【作者】 杨小波；

【导师】 杜希文；

【作者基本信息】 天津大学 ， 材料学， 2008， 硕士

【摘要】 本文将脉冲激光液相烧蚀法和物质的相分离相结合,提出一种制备圆盘状纳米结构的新方法,成功制备出硅纳米圆盘和碳化硅纳米圆盘,并对纳米圆盘的形成机制做了相关研究,主要内容如下:(1)利用脉冲激光液相辐照SiO粉末在去离子水中的悬浮液,研究了SiO在激光引起的极端非平衡条件下的相分离过程,成功制备出硅纳米圆盘;(2)通过改变液相介质、激光脉宽、激光辐照时间和固相原料以及快速退火SiO粉等对比实验,确定了Si纳米圆盘是通过激光引起的固态相分离形成的;(3)利用脉冲激光液相烧蚀SiOC非晶粉末在去离子水中的悬浮液,成功制备出碳化硅纳米圆盘,证实激光诱导固态相分离是一种制备纳米圆盘的普适方法。更多还原

【Abstract】 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.更多还原