XANES and luminescence studies of M₂O₃-CaO-SiO₂-B₂O₃ (M₂O₃ = Y₂O₃ and La₂O₃) glasses doped with Dy³⁺ ions

The Dy³⁺-doped glasses of the M₂O₃: CaO: SiO₂:B₂O₃ (M₂O₃ = Y₂O₃ and La₂O₃) materials have been successfully fabricated with the 0.5 % mol of the Dy₂O₃ concentration, and thoroughly investigated based on the physical, optical, photo- and radioluminescence properties. The developed glass materials were prepared from the compositions of 25M₂O₃: 10CaO: 10SiO₂: (55-x)B₂O₃: 0.5Dy₂O₃ by the conventional melt-quenching technique at 1, 400°C. The clear sample of the doped La₂O₃ glass demonstrated higher density and the molar volume than those of the doped Y₂O₃ glass. From the spectrophotometry, the absorption peaks of the Dy³⁺ ions were clearly observed in both glasses. The photoluminescence (PL) spectra of the developed glasses indicated two-colors with two strongest peaks at 577 nm (⁴F_9/2→⁶H_13/2) and 482 nm (⁴F_9/2→⁶H_15/2). In addition, the emission spectra from the radioluminescence (RL) were identical to those from the PL measurements. From the results of the PL and RL measurements, the Y₂O₃ glass had higher emission in the intensity than the La₂O₃ glass. The X-ray absorption near edge spectroscopy (XANES) with the synchrotron radiation was carried out in fluorescent-yield mode to determine the average oxidation number of the Dy ions dispersed in the glass matrices. The Dy L₃-edge XANES spectra of both developed glasses were nearly identical with the sharp white line at 7795.5 eV and the edge energy of 7793 eV. Compared to the XANES spectrum of the pure Dy₂O₃ standard, both glasses showed the difference smaller than 0.5 eV, and therefore confirmed the oxidation number of the Dy ions of 3+.