Photoluminescence from terbium doped silica-titania prepared by a sol-gel method

Terbium doped (0.5 at.%) TiO2-SiO2 (30%/70%) was prepared by a sol-get method. X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) were used to characterize the powder calcined at two different temperatures. At a low temperature of 550 degrees C an amorphous phase was obtained, but at a higher temperature of 1000 degrees C, the anatase TiO2 phase was crystallized in the amorphous SiO2 phase. Green photoluminescence from ultraviolet excitation was detected after heating to either temperature, but the amorphous sample heated to 550 degrees C exhibited a higher intensity. X-ray diffraction and photoluminescence excitation data are discussed to explain these observations. (C) 2006 Elsevier Ltd. All rights reserved.