X射线激光Nd薄膜靶表面氧化特性研究

CHARACTERIZATION OF SURFACE OXIDATION OF Nd FILM X-RAY LASER TARGET

利用石英晶体振荡技术测量了不同环境中稀土元素 Nd薄膜靶表面氧化速率 ,用俄歇电子能谱 ,扫描电镜 ,X射线衍射 ,X射线光电子能谱分析了 Nd薄膜表面氧化过程 ,发现保存环境对靶的表面氧化行为有重要影响。空气中水分是引起 Nd快速氧化的关键因素。表面氧化层为团聚状的非晶结构 ,氧化物与金属的体积比较小可能是引起 Nd薄膜较易氧化的原因。Nd薄膜靶表面覆盖有一层氢氧化物 ,其厚度按保存在真空、干燥空气和潮湿空气环境而依次递增。

Quartz crystal oscillation technique was applied to measure the increase of oxide scale on Nd film targets and Auger electron spectroscopy was used to analyze the depth distribution of oxygen and neodymium. Scanning electron microscopy, X-ray diffraction and X-ray photonelectron spectroscopy were used to characterize oxide scale. Results show that the environment where Nd films were stored plays a great role in the oxidation behavior of the Nd films. Water contained in the atmosphere is the key factor for the rapid oxidation of the Nd film. The scale is amorphous and shows steamed bread like surface. The small ratio of the oxide volumn to the metal volumn may be the cause of the Nd inclining to oxidation. The scale is covered by a layer of hydroxide. the thickness of the hydroxide is the least for the films in vacuum, the second in dry air and the greatest in humid air.