| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1618399 | Journal of Alloys and Compounds | 2011 | 5 Pages |
Yb3+ doped and Yb3+/Tb3+ codoped aluminum silicate glass with good transparency has been synthesized using the sol–gel process. X-ray diffraction (XRD), scanning electron microscopy (SEM), differential thermal analysis (DTA) and thermo gravimetric analysis (TGA) techniques have been used to distinguish between glassy and glass ceramic structures while FTIR spectrum is measured to see if the vibrational frequencies of prominent modes change and thus provide identifying feature. A study of the upconversion luminescence from Tb3+ indicates that cooperative energy transfer from Yb3+ to Tb3+ ions is not operative in the glass host but adds to the luminescence in the glass ceramic and the ceramic forms of the host. The exciting radiation is 976 nm from a diode laser. Dependence of the luminescent intensity as a function of the input radiation power indicates involvement of two incident photons. Emission of Yb3+ has also been investigated and it is observed that the cooperative emission (at 488 nm) is dependent on the concentration and temperature of the host. Luminescent emission spectrum of terbium ion on excitation by 355 nm radiation is also recorded and compared with the upconverted luminescence excited by 976 nm radiation.
► Structural properties of glass, glass ceramic and ceramic have been investigated. ► Absorption of Yb3+ in the glass ceramics is many times stronger than in the glass. ► Yb3+ gives cooperative upconversion in glass ceramic and ceramic (fully crystalline). ► There is no Stark splitting observed in the emission of Tb3+ ions on 976 nm excitation while Stark splitting is observed in the case of 355 nm excitation source.
