摘要
本文报导产自我国几个主要萤石矿床中若干萤石样品的阴极射线发光谱.除样品Mo-25以外,所研究样品发光谱的主要谱线均来源于取代Ca^(2+)的Dy^(3+)和Sm^(3+)离子的f-f跃迁.此外,还观察到几条Er^(3+)、Pr^(3+)和Tb^(3+)离子的发光谱线.谱线的相对强度与样品中各种稀土离子的相对含量有关.群论分析表明,萤石中Dy^(3+)离子的局部对称性低于立方,或者存在着一种以上的Dy^(3+)环境.在稀土含量最低的样品(Mo-25)的谱中,可见区只观察到一条中心在490nm处的宽带,它可能是Mn^(2+)离子的~4T_(1g)(G)→~4A_(1g)(G)跃迁产生的.由于萤石中Mn^(2+)的晶场分裂参量Dq反常地低,故能产生八配位Mn^(2+)离子少见的绿色发光.
Cathodoluminescence spectra of a suit of natural fluorites from several main fluorite deposits of China were measured.The main lines in the spectra of all samples studied, except Mo-25, are due to Dy3 + and Sm3+ ions substituting for Ca2 + . A few lines arising from Er3+, Pr3+ and Tb3+ are also observed.The relative intensities of spectral lines are closely related to the relative contents of individual rare earth ions in the sample. Group theory analysis shows that the local symmetry of Dy3+ in fluorite is lower than cubic and/or there may exist more than one Dy3+ environments. In the spectrum of Mo-25, only a broad band centered at 490 nm occurs in the visible region. This band is probably due to the 4T1gS(G)-6A1g(G) transition of Mn2+ ions.Because the crystal-field splitting parameter Dq of Mn2+ in fluorite is anomalously low, grean emission is observed, which is unusual for eightfold-coordinated Mn2 + ,
出处
《发光学报》
EI
CAS
CSCD
北大核心
1992年第3期220-225,共6页
Chinese Journal of Luminescence
基金
中国科学院长春物理研究所激发态物理开放研究实验室资助
