Danburite luminescence

The narrow band at 437 nm with a decay time of 650 ns in the danburite luminescence spectrum belongs to Eu " luminescence (Fig. 4.15a), which was also detected by steady-state spectroscopy (Gaft et al. 1979). Besides that, under 308 nm excitation narrow lines appear at 580, 592, 611, 618, 655 and 692 nm (Eig. 4.15c) with a long decay time, which confidently may be ascribed to Eu. Under 266 nm excitation another group of hnes appear with the main line at 575 nm connected with a different type of Eu " (Fig. 4.15d). 

The narrow band at 437 nm with decay time of 650 ns in danburite luminescence... 

Danburite is calcium borosilicate with an orthorhombic structure (2/m2/ mljm) and space group Pnam. The natural danburite in our study consisted of five samples from a variety of geologic environments. Concentrations of potential luminescence impurities in one sample are presented in Table 4.8. 

The luminescence centers Eu ", Yb, Ce, Dy, and Sm + characterize the steady-state spectra of danburite (Gaft et al. 1979 Gaft 1989). By using laser-induced time-resolved spectroscopy we were able to detect the following emission centers Ce, Eu, Eu, Sm ", Dy (Fig. 4.15)... 

Fig. 4.15. a-d Laser-induced time-resolved luminescence spectra of danburite demonstrating Ce, Eu and Eu ... 

Fig. 5.22. Luminescence and excitation spectra of in danburite and datolite (Gaft and Gorobets 1979)...

Fig. 4.28 (a-b) Laser-induced CW luminescence spectra of danburite demonstrating Eu and Nd centers... 

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