准分子激光作用下二氧化钛的表面变性

适当能量密度的准分子激光作用于二氧化钛时，电导性能发生了显著的变化，室温下从原来的绝缘体转变为半导体，同时表面颜色也发生了变化．利用X射线衍射、X射线光电子能谱及显微分析等多种测试方法进行了分析、比较，确定了该过程是由于短脉冲的准分子激光作用，造成了二氧化钛的快速升温熔化和快速冷凝重构，导致氧的缺位，引起了化学配比偏离．用热传导方程对能量密度阈值进行了近似估算，结果与实验基本相符 关键词：

SURFACE CHARACTER OF TITANIA CHANGED BY EXCIMER LASER

The electric conductivity changes markedly when titania is irradited by a proper-fluence excimer laser, it changes from insulator to semiconductor at room temperature, and its color changes too. Several titania samples before and after irradiation are studied with XRD, XPS and microscopic analyses. It is observed that the changes takes place when proper-fluence excimer laser pulse irradites the surface of titania and the temperature of the surface rises quickly. A thin layer of the irradited area melts quickly and soon resolidifies. This leads oxygen in titania to vacate partly, so the stoichiometry of the sample deviates from the normal value. The laser fluence threshold is estimated by the equation of heat transfer and the result agrees approximately with the experiment.