Nature of color centers in silicate glasses with additions of cerium and titanium oxides

Abstract

Translated from Steklo i Keramika, No. 7, pp. 9 -13, July, 2009. Silicate glasses with additions of cerium and titanium oxides are studied. Such glasses are of interest for manufacturing electric lights for automobile headlights and heat-stable light filters. It is established that the characteristic yellow-orange color is due to the formation chromophoric centers containing products from the interaction of cerium and titanium oxides. It is proposed on the basis of optical transmission and photoluminescence measurements as well as XPES data obtained for the composition used in light filters that titanium and cerium are present predominately as the ions Ti 4+ , Ce 3+ , and Ce 4+ .The topicality and importance of the problem of developing new optical materials in the glass industry are due to the possibility of controlling their colorimetric characteristics. The glasses must function reliably and keep their optical properties. Examples are glasses for electric lights in automobile headlights, light filters, and other light-engineering articles. The introduction of transition and rare-earth elements capable of coloring the glass matrix as added compounds is one method that is often used to obtain different color hues of glass [1], but such problems are mainly solved empirically. Transition and rare-earth elements introduced into glass can be in the form of ions and chromophoric centers with different composition or they can form small clusters of atoms and nanocrystalline phases (oxides, chalcogenides (provided chalcogens are introduced), and others).All this makes it necessary to investigate in greater detail the physical -chemical aspects of the state of the form in which heavy elements -in the present work, cerium and titanium -are present in glasses.Glasses with a combination of CeO 2 and TiO 2 additions are one promising variant of optical materials for manufacturing near-UV and visible range light filters [2, 3]. The particulars of the electronic structure of cerium and titanium ions make selective absorption possible, and when these ions are present together double oxides can form and the lowest valence states can be stabilized, thereby expanding the optical and functional properties of the glasses.The present work is devoted to the synthesis and investigation of the properties of silicate glasses when the additions are in the form of combinations of cerium and titanium oxides in a wide range of molar ratios in order to determine the states of these elements in the glasses and to clarify the possible nature of the chromophoric centers which are formed. This work is a continuation of previous studies [4] but with a substantially expanded range of concentrations of the added elements and using photoluminescence and x-ray photoelectron spectroscopy (XPES).A glass matrix based on the aluminosilicate bariumstrontium glass-forming system SiO 2 -Al 2 O 3 -MgO -CaOBaO -SrO -Na 2 O -K 2 O -Li 2 O was used. Two series of glasses with the TiO 2 content varying from 0 to 25% 5 were chosen for these investigations: 1 -...

Structural Features and Synthesis of CeO2-Doped Boroaluminosilicate Oxyfluoride Transparent Glass Ceramics

“…Raising appropriately CeO 2 content yields more Ce 3+ ion that consequently give rise to number of NBOs [12]. Cerium in lower content presents predominantly in Ce 3+ state yielding more NBOs, while in higher content more Ce 3+ will transform into Ce 4+ suppressing the rising NBOs concentration instead [12,48]. Then variation in NBOs concentration as function of cerium content will have potential effect upon the nonlinear variation in connectivity of silicate network and borate network.…”

Excellent Mechanical Properties of the Silicate Glasses Modified by CeO2 and TiO2: a New Choice for High-Strength and High-Modulus Glass Fibers

“…However, the increases in the cerium and titanium concentrations sequentially carry off a large number of bridge oxygen bonds, as shown in Eq. ( 9) [37].…”

Poly[tetraaquatriglutaratodicerium(III) decahydrate], a novel luminescent metal-organic framework possessing hydrophilic hexagonal channels

“…The chemical structure and the tunability of the position of the strong 4f-5d absorption and the corresponding emissions make Ce 3+ ion one of the important constituents in light emitting materials. 33,34 The solid state PL spectrum of the complex was recorded using JY Horiba PL meter at room temperature with an excitation wavelength of 300 nm and the spectrum is displayed in Figure 11. The spectrum of Ce(III) shows broad emission band as the emission which result from 4f-5d transitions are generally broad.…”