Crystallization effects on the photoluminescence efficiency of SrO-BO glass activated by W, Eu, Dy or Pr ions.

Binary strontium borate host glass together with samples doped with 0.25 %WO and one of the rare - earth ions (0.125% Eu, Dy or Pr) were prepared by conventional melting - annealing technique. DTA analysis of the host base glass was carried out to derive the proper temperatures which are necessary to convert glasses into their corresponding glass -ceramic through controlled thermal heat -treatment regime. Measurements of optical, FTIR, and PL spectra were carried out with special analysis of the spectral properties. The identity of glass - ceramic derivatives were investigated through x-ray diffraction, and TEM & SEM tools to identify their crystalline morphological features. The absorption spectrum of WO - doped glass refers to the existence of dominant hexavalent tungsten ions. The RE- doped glass reveal characteristic visible - NIR absorption peaks due to the respective rare earth ions. FTIR spectra show absorption bands due to both triangular and tetravalent borate groups (BO, BO).PL spectra reveal excitation and emission characteristic peaks due to each specific rare earth ions. XRD indicate the preference of the host glass to form strontium pyroborate (SrBO) crystalline phase. This facilitates the clear knowledge of the crystallization behavior and hence can justify the effect of the crystallization on the studied properties.