金属基质激光诱导击穿光谱最佳离焦量的基质效应研究  

An Exploration of Matrix Effect on Optimal Defocus Distance of Metal Matrix in Laser-Induced Breakdown Spectroscopy

作　　者：傅院霞 贾韧[1] 徐鹏 薛玲 姚关心 郑贤锋[1,3] 秦正波 杨新艳[1,3] 崔执凤 Fu Yuanxia;Jia Ren;Xu Peng;Xue Ling;Yao Guanxin;Zheng Xianfeng;Qin Zhengbo;Yang Xinyan;Cui Zhifeng(College of Physics and Electronic Information,Anhui Normal University,Wuhu 240002,Anhui,China;Department of Science,Bengbu University,Bengbu 233030,Anhui,China;Key Laboratory of Photoelectric Materials Science and Technology of Anhui Province,Wuhu 240002,Anhui,China)

机构地区：[1]安徽师范大学物理与电子信息学院,安徽芜湖240002 [2]蚌埠学院理学院,安徽蚌埠233030 [3]光电材料科学与技术安徽省重点实验室,安徽芜湖240002

出　　处：《中国激光》2022年第13期152-160,共9页Chinese Journal of Lasers

基　　金：国家自然科学基金(61475001,12074004,61805002);安徽省重点研究与开发项目(1804a0802193);安徽省自然科学基金(1808085MA22);安徽省高等学校自然科学研究重点项目(KJ2019A0857,KJ2020A0752)。

摘　　要：在激光诱导击穿光谱(LIBS)技术中,离焦量的选取对LIBS的探测灵敏度具有重要影响。LIBS光谱强度最大时对应的最佳离焦量具有基质效应,不同物理特性的金属基质样品具有不同的最佳离焦量。通过实验测定了12个物理性质有明显差异的高纯金属样品的最佳离焦量,初步推测了最佳离焦量与金属基质元素物理特性参数之间的关联,所得结论支持前期LIBS击穿阈值的研究结果。本文研究结果表明金属基质元素的力学、光学、电学和热学特性对最佳离焦量有影响,尤其是基质金属元素的热导率和比热容对最佳离焦量影响很大,且都与最佳离焦量正向关联。本文依据基质元素物理特性参数的本质对最佳离焦量的基质效应机理进行了合理分析,分析结果对进一步理解LIBS技术中的基质效应机理和修正基质效应提供了基础支撑。Objective Laser-induced breakdown spectroscopy(LIBS)is widely used in various fields,such as agriculture,industry,national defense,energy,aerospace,natural science,and interstellar physics,because of its unique advantages.However,low detection sensitivity and accuracy have hindered the expansion of LIBS,and many researchers have worked to improve the detection sensitivity and reduce measurement errors.Optimizing the experimental parameters is important in LIBS.The maximum intensity or signal-to-noise ratio of a LIBS signal under the optimal experimental parameters is an important means of improving the LIBS detection sensitivity.However,studies on the effect of sample matrix properties on the optimal detection system,which we call the matrix effect of the optimal experimental parameters,are scarce.Therefore,the matrix effect of the optimal experimental parameters must be studied for selecting the standard samples in the calibration method and improving the LIBS characteristics.The distance between the focal position of the laser beam and sample surface(defocus distance)is an important experimental parameter of a LIBS system during LIBS analysis.Optimizing this parameter ensures that the LIBS signal has the strongest intensity.Therefore,the intrinsic connection between the physical properties of the matrix and optimal defocus distance must be studied to select a suitable matrix for enhancing the LIBS signal and selecting a reference sample for the calibration method.We could not find other studies focusing on the correlation between the metal matrix and optimal experimental parameters.Methods Considering that the interaction of nanosecond pulsed laser and metallic materials to form a plasma involves the evaporation of metallic materials,interaction of vapors with laser,and plasma radiation,this work studies the influence of the matrix physical properties(density,hardness,optical absorption coefficient,ionization energy,electric conductivity,thermal conductivity,specific heat capacity,melting point,boiling point,la

关 键 词：光谱学 激光诱导击穿光谱 金属 基质效应 物理特性 最佳离焦量 

分 类 号：O433[机械工程—光学工程]