激光诱导的钛酸钡等离子体的时间分辨光谱

Time-Resolved Spectroscopy of Laser Induced Plasma from BaTiO_3

利用光学多通道分析仪（OMAⅢ）研究脉冲激光沉积钛酸钡薄膜过程中的激光诱导等离子体的时间分辨发射光谱。利用各种粒子不同时刻发射的谱线强度描绘成该粒子的飞行时间谱，表征了等离子体中该粒子的空间浓度分布。根据飞行时间谱的特征，推算了粒子束脉冲（等离子体）的空间宽度及其与缓冲气体压力的关系。提出了在激光沉积多元氧化物薄膜过程中的合适的缓冲气体压力范围，解释了激光原位沉积高温超导薄膜中所需氧气分压达30Pa的原因。

The time- resolved luminescence spectra of laser induced plasma from BaTiO3 were studied with a optical multichannel analyzer (OMA Ⅲ). The time-of-flight spectra of various particles, by which the concentration distribution of the responded particles was represented, were built by the emissive intensity of the same particles at different time. The spatial length of the ejected pulsed particle beam (i. e. plasma) was evaluated by the time-of-flight spectra, and the dependance of its dimension on the partial pressure of the buffer gas was deduced. Furthermore, a optimun partial pressure range of buffer gas for laser deposition of oxides films with multielement was suggested, and the necessity of about 30 Pa oxygen partial pressure during laser deposition of high Tc superconducting films is explained.