The Preparation And Luminescence Properties Of Rare Earth Ions-doped Oxyfluoride Glass And Glass Ceramics

In this paper, Eu³⁺, Ce³⁺ and Dy³⁺ doped oxyfluoride glass and glass ceramics were prepared, respectively. The crystallization process and luminescence behaviors were studied.Eu³⁺ doped lead fluorosilicate and alkaline earth fluorosilicate glass and glass ceramics were prepared, respectively. The variety of local environment around Eu³⁺ was studied using the Phonon Side Band (PSB) spectra and the Judd-Ofelt theory. The results indicated that Eu³⁺ ions were embedded in CaF₂, SrF₂ and BaF₂ nano-crystallites, which were precipitated from the alkaline earth fluorosilicate glass by heat-treating process. The similar result could be acquired in the lead fluorosilicate glass ceramics containing β-PbF₂ nano-crystallites. However, Eu³⁺ could not enter into the MgF₂ crystal phases in the glass ceramics containing MgF₂ nano-crystallites.The Ce³⁺ or Dy³⁺ doped glass and glass ceramics containing CaF₂ were prepared. The intense luminescent behaviors of Ce³⁺ ions were acquired in both glass and glass ceramics but the luminescent intensities of Dy³⁺ in those hosts were very weak. The Ce³⁺/Dy³⁺ co-doped alkaline earth (Ca, Sr, Ba) fluorosilicate glass and glass ceramics were prepared. No crystal diffraction peaks were found in XRD patterns of the quenched samples containing CaF₂, while the SrF₂ and CeF₃ crystal phases could be found in the quenched samples containing SrF₂ and BaF₂, respectively. The CeOF and CeF₃ crystal phases could be acquired by heat-treating the glass containing CaF₂ and the luminescent intensities of Ce³⁺ and Dy³⁺ were enhanced in glass ceramics. The luminescence of Dy³⁺ was ascribed to the energy transfer from Ce³⁺ to Dy³⁺. The luminescent intensity of Dy³⁺ was enhanced with the increase of the co-doped ratio of Ce³⁺ to Dy³⁺. The Commission Internationale de l'Eclairage (CIE) chromaticity coordinates of the Ce³⁺/Dy³⁺ co-doped samples were approximate purplish white.The Ce³⁺/Dy³⁺/Eu³⁺ tri-doped calcium fluorosilicate glass and glass ceramics were prepared. The CeOF and CeF₃ crystal phases precipitated from glass host and the luminescence intensity of Ce³⁺ was increased markedly by heat-treating precursor glass samples. The approximate white light emissions were acquired successfully with the variation of Dy³⁺/Eu³⁺ concentration ratios and the variation of excitation wavelength in the region of 310 nm-320 nm and in the vicinity of 393 ran.