Preparation and up-conversion luminescence of Tb3+/Yb3+ co-doped BaO-WO3-SiO2 glass ceramic.

The Tb 3+ /Yb 3+ co-doped BaO-WO 3 -SiO 2 glass ceramic is prepared by melt crystallization method. The optimum heat treatment schedule is determined on basis of differential scanning calorimetry. The crystal phase is BaWO 4 by X-ray diffraction analysis. The crystal grain sizes are examined by scanning electron microscope and crystal grain sizes increase with the increasing of heat treatment time. In the visible region, the transmittance of glass ceramic is 79%. The up-conversion fluorescence intensity increase with the increasing of heat treatment time up to 90 min and with the increasing of Yb 3+ concentration up to 0.3 mol%. The possible mechanism of up-conversion in Tb 3+ /Yb 3+ co-doped BaWO 4 glass ceramic is discussed. [ABSTRACT FROM AUTHOR]