Thermal, mechanical, and upconversion properties of Er3+/Yb3+ co-doped titanate glass prepared by levitation method

A novel Er3+/Yb3+ co-doped titanate glass sphere with diameter of 3.5 mm has been successfully fabricated by levitation method. Its thermal stability, mechanical property and upconversion behavior were investigated. The glass transition temperature T-g, onset crystallization temperature T-c, and peak crystallization temperature T-p, are as high as 820, 895 and 902 degrees C, respectively. Its Vickers hardness is found to be up to 7.85 GPa. Intense green and red upconversion emissions were obtained in this glassy sample upon 980 nm excitation. The results illustrate good potential of this class of material for practical application in frequency upconversion device. In addition, it is found that heating treatment above T-p can reduce the efficiency of upconversion fluorescence as well as deteriorate the mechanical property, due to the occurrence of La4Ti9O24 crystals. (C) 2011 Elsevier B. V. All rights reserved.