红外和拉曼光谱在金属氢化物结构分析中的应用

摘要

红外光谱和拉曼光谱是分析金属氢化物结构的强有力工具,通过红外、拉曼光谱分析并结合理论计算,可以获得二元(MgH2,CaH2,AlH3)和三元(Mg2 FeH6)金属氢化物中金属原子与氢原子局域成键环境信息,从而鉴别金属氢化物不同的相结构,还可以获得三元金属氢化物M2 RuH6(M=Ca,Sr,Eu)中由于金属原子的不同而导致的结构差异,以及三元金属氢化物与其氘化物的结构差异.利用原位拉曼光谱分析技术分析高压或高温下金属氢化物的形成与分解反应过程,可以获得金属氢化物在高压加载及卸压过程中的结构变化,更好的理解金属氢化物的衍射数据.PAIR(photoacoustic infrared spectroscopy)光谱技术增强了红外活性和拉曼活性组合谱带的强度,从而避免了空气及潮湿环境对傅里叶红外变换光谱实验结果的影响.红外光谱和拉曼光谱用于金属氚化物的结构分析,获得金属氢化物中金属原子与氢同位素原子局域成键环境的差异,更好的研究氢同位素效应.而且,拉曼光谱已被成功用于分析氢同位素混合气体的组成.因此,将金属氢化物结构的红外和拉曼光谱分析与氢同位素气体组分的拉曼光谱分析相结合,可用于研究金属与氢同位素气体反应的动力学过程及同位素效应.%Infrared and Raman spectroscopy are powerful technologies in metal hydrides structure analysis .If theoretical calculation is combined with Infrared and Raman analysis technology ,they can provide information on the local bonding environment between metal atoms and hydrogen atoms of binary (MgH2 ,CaH2 ,AlH3 ) and ternary (Mg2 FeH6 ) metal hydrides .Thereby , different phase structures of metal hydrides can be identified ,they can also provide structure difference information in ternary metal hydride M2 RuH6 (M= Ca ,Sr ,Eu) due to the different metal atom composition ,and the structure differences between ternary metal hydride and deuteride also can be obtained .Moreover ,the structure change of metal hydride can be monitored during compression and decompression by in situ Raman spectroscopy analysis ,which helps us interpret diffraction data deeply .In order to avoid the disadvantageous effect of air and moisture on FTIR experiment results ,PAIR spectrum was developed to increase the intensities of Infrared and Raman combination bands .Infrared and Raman spectroscopy even can be applied on metal tritides structure analysis ,and it can provide the information on the local bonding differences between metal atoms and hydrogen isotopic atoms which helped us research the hydrogen isotopic effect better .Raman spectroscopy has also been used to in situ monitoring of the formation and decomposition of metal hydride under high pressure or high temperature ,and has also been successfully applied in hydrogen isotope mixture gases analysis ,such as tritium analysis and management in ITER project .If structure analysis is combined with hydrogen isotope mixture gas analysis by Infrared and Raman ,the reaction kinetics and isotopic effect between metal and hydrogen isotope gases reaction can be researched .