Synthesis of SiO2-TiO2:Yb3+ glass-ceramics and characterization of structure and optical properties

Abstract

In this work, the monoliths of  85 % SiO₂-15 % TiO₂ doped Yb³⁺ ions at different contents have been prepared by sol-gel method. The measurement of FT-IR, Raman spectroscopic and XRD analysis show the formation of anatase TiO₂ nanocrystals with average size about 15–20 nm in silica matrix. Moreover, the pyrochlore crystals of Yb_2­Ti₂O₇ begin to form in the samples when content of Yb³⁺ reaches to 1 mol %. The energy transferred  from TiO₂ crystals to Yb³⁺ ions is proven by the characteristic emission spectrum of Yb³⁺ at the wavelength of 980 nm when the samples are excited by the wavelength of 300 nm. The photoluminescence intensity is highest at 0.1% mol of Yb³⁺ and gradually decreases with doping contents.