(CrO4)络离子中Cr-O距离的研究

通过MS-X_α方法的计算详细地讨论当Cr—O距离变化时(CrO₄)络离子的电子结构和能级分布。给出铬离子三种不同价态(Cr²⁺,Cr³⁺,Cr⁴⁺)的单电子轨道能量、电荷分布、基态电子组态、低激发态的光学跃迁,以及能级示意图。当配位体与中心离子的距离R≤2?时,用晶场理论得出的结果不能令人满意。这时必须考虑配位体与中心离子距离的影响,以及中心离子(对于过渡族金属离子而言)的4s或4p原子轨道的作用。 关键词：     

BeAl_6O_(10)晶体中单体铬和铬离子对的窄线发光

BeAl_6O_(10):Cr的荧光谱由宽带和七条窄线组成.在室温下,宽带和窄线发光的衰减时间极不相同.本文根据线强度的温度关系、浓度关系推论,三条窄而强的荧光线来自两种单体铬中心.另有两条稍宽的线来自铬离子对中心.宽带发射与这些窄线发射没有象BeAl_2O_4:Cr中那样的联系.     

ANALYSIS OF THE LASER-INDUCED FLUORESCENCE IN CRYSTAL Cr:Mg2SiO4

Observation of the 532 nm-laser-induced fluorescence spectra of two kinds of Cr:Mg₂SiO₄ crystalline samples grown in different atomsphere are reported. The experiments were con-ducted at both room temperature and liquid-nitrogen temperature. The fluorescence spectra of the two kinds of samples were different with respect to the polarizing direction of the inducing leser, and two emission bands with different polarized characters and various en-hancement in intensity at low temperatures were also found. In the light of the calculated results by Ms-X_α method, the main experimental results are explained.