氧化金激光诱导荧光光谱:b^4π^3/2-X^2π^3/2跃迁  

The Laser-Induced Fluorescence Spectrum of Gold Monoxide(AuO):b^4π^3/2-X^2π^3/2 Transition

作　　者：向前兰 杨杰[3] 华雪侠[1] 张吉才 马新文[3] XIANG Qian-lan;YANG Jie;HUA Xue-xia;ZHANG Ji-cai;MA Xin-wen(Ion Beam&Optical Physical Joint Laboratory of Xianyang Normal University and Institute of Modern Physics,Chinese Academy of Sciences,Xianyang 712000,China;Department of Applied Physics,Xi’an Jiaotong University,Xi’an 710049,China;Institute of Modern Physics,Chinese Academy of Sciences,Lanzhou 730000,China)

机构地区：[1]咸阳师范学院与中国科学院近代物理研究所联合共建离子束与光物理实验室,陕西咸阳712000 [2]西安交通大学应用物理系,陕西西安710049 [3]中国科学院近代物理研究所,甘肃兰州730000

出　　处：《光谱学与光谱分析》2020年第6期1747-1750,共4页Spectroscopy and Spectral Analysis

基　　金：国家自然科学基金项目(11274316,U1832175,11605147)资助。

摘　　要：研究Au-O键可以帮助人们更好理解不断发展的金化学科学,而氧化金AuO是含Au-O键最简单的模型,因此对氧化金分子的电子态结构进行研究有重要的科学意义。激光诱导荧光光谱是研究分子结构和化学键的有效手段。利用激光溅射结合超声射流技术产生气相氧化金分子(AuO),采用激光诱导荧光光谱技术测量氧化金在16500~18500 cm^-1范围内的电子谱。消融激光(Leibao Dawa-300)溅射高纯度(99.9%)金靶产生金原子,将靶材安装在真空步进电机上由步进电机带动转动,保证溅射激光每次打在靶材不同的位置,保证信号的稳定度。高压纯氧气经脉冲阀(Parker,General Valve,series 9)进入真空腔室与金原子反应生成气相氧化金分子AuO。Nd∶YAG激光器(Continuum SureliteⅡ-10)泵浦染料激光器(Sirah,Cobra-Stretch)输出线宽为0.05 cm^-1、脉宽为5 ns、能量为0.1 mJ·pulse-1的激光,该激光激发前述产生的氧化金分子至激发态。扫描染料激光器,使用光电倍增管PMT(EMI,ET9202QB)探测此荧光。示波器卡(Picoscope 6404C,500 MHz,14 bits)将光电倍增管探测的信号转换成数字信号输入到计算机,采用基于LabVIEW的分析程序读取信号。分析所测量的光谱,带头在17152.94,17552.17,17932.78和18291.62 cm^-1的四个振转谱带被归属为b^4π^3/2(v′=0,1,2,3)-X^2π^3/2(v″=0)跃迁谱。对转动分辨的光谱进行拟合,得到激发态b^4π^3/2态的光谱常数,包括转动常数和离心畸变常数。分析了激发态可能的电子组态,为1σ^21π^41δ^42σ^12π^33σ^*1。Studying Au-O bond can provide an insight into the rapidly expanding field of gold chemistry.AuO is the simplest model containing Au-O bond.So,it is of great scientific significance to study the electronic structure of gold oxide molecule.Laser induced fluorescence spectroscopy is an effective means to study molecular structures and chemical bonds.In this paper laser ablation combined with ultrasonic jet technology was used to produce gas phase gold monoxide,and the electronic spectrum of the gaseous gold monoxide molecule(AuO)had been investigated in the range of 16500~18500 cm^-1 using laser induced fluorescence spectroscopy.The ablation laser(Leibao Dawa-300)sputtered pure gold target(99.9%)which was controlled by a vacuum motor for rotation to produce Au atoms.The pure high pressure O2 was injected into the vacuum chamber through a molecular beam pulse valve(Parker,General Valve,series 9)to react with the gold vapor to form AuO.A dye laser(Sirah,Cobra-Stretch)was pumped by Nd∶YAG laser(Continuum Surelite II-10)and the output of the pulsed dye laser(linewidth 0.05 cm^-1,pulse duration 5 ns,energy 0.1 mJ·pulse-1)was introduced into the vacuum chamber to excite AuO.The fluorescence from the excited AuO radical was imaged through appropriate low-pass cutoff filters into a photomultiplier tube(PMT)detector(EMI,ET9202 QB).Pulsed analog signals from the PMT were converted into digital signals by a fast digital oscilloscope card(Picoscope 6404 C,500 MHz,14 bits)and recorded by a data acquisition program based on LabVIEW of our own.The detected bands with band heads at 17152.94,17552.17,17932.78 and 18291.62 cm^-1 were attributed to b^4π^3/2(v′=0,1,2,3)-X^2π^3/2(v″=0)transitions.The molecular constants including rotational constants and centrifugal distortion constants were determined by analyzing the rotationally resolved spectra.The possible electronic configuration of the excited state is 1σ^21π^41δ^42σ^12π^33σ^*1.

关 键 词：AuO 激光诱导荧光光谱 电子谱 

分 类 号：O561.3[理学—原子与分子物理]