刚玉类宝石的光致发光光谱研究

Study on Photoluminescene Spectra of Corundum Gemstone

采用532nm固体激光器作为激发源研制了一套计算机自动控制的微区光致发光分析系统,从发光光谱角度分别对来自于不同地区的刚玉样品的结构、所含杂质等信息进行了光谱分析和研究。结果发现,在650～730nm波段的光致发光谱中,都存在Cr3+的694.2nm特征峰,表明所有样品中都存在Cr元素;而红宝石样品的发光谱中还分别呈现669、708.6、714nm谱峰,光谱结构明显复杂于蓝宝石样品,表明Cr3+在不同样品中替代Al3+而形成不同晶体结构;与其相同波段的阴极发光谱相比,受荧光产额规律的影响,缅甸和越南红宝石样品的光致发光谱中呈现更多谱峰,可见光致发光光谱能反映样品的结构、所含杂质等信息,是一种灵敏度及选择性都较高的分析方法。

A suit of computer auto-control photoluminescence(PL)detection schemes were performed with 532 nm solid-state laser as an exciting source.Corundum samples were studied from different regions respectively.In the 650~ 730 nm PL spectra,the results show that characteristic peak of Cr3+ at 694.2 nm exists,and it indicates all samples contain Cr;there are three peaks at 669 nm,708.6nm,714 nm in emission spectra of ruby samples,and their spectral structures are more complicated than sapphire samples',then it indicates different crystal structures are formed because of substitution Al3+ by Cr3+.Compared with their corresponding cathodoluminescence spectra,there are more peaks presented in PL spectra of ruby samples from Burma and Vietnam influenced by fluorescence yield rules.It is obvious that PL spectra can contain some useful information from samples related to their structures and impurities and is an analysis method with high sensitivity and selectivity.