Devitrification Behavior of Sol-Gel Derived ZrO2-SiO2 Rare-Earth Doped Glasses: Correlation between Structural and Optical Properties

Abstract

Optical and structural properties of glasses and glass-ceramics (GC) obtained by different heat-treatment of Tb and Tb-Yb doped sol-gel derived 30ZrO2-70SiO2 materials were investigated. A glass was formed after treatment at 700 °C whereas devitrification of the media after the treatment at 1000 and 1100 °C, led to the formation of GC containing up to three different crystalline phases, namely, tetragonal ZrO2, Yb-disilicate and cristobalite. The modification of the optical properties through the heat treatment was caused by redistribution of the rare earth elements (REE) among the different phases: both Tb and Yb entered the t-ZrO2 lattice, Yb can also be present in the form of a Yb2Si2O7 crystal. Devitrification led to an increase in Tb→Yb energy transfer efficiency as compared to the glass, though it was higher in the samples heat-treated at 1000 °C than in those treated at 1100 °C. The most intensive Yb3+ luminescence, induced by the energy transfer from the Tb3+ ion, was observed at the interface between t-ZrO2 and the glassy phases, due to the high concentration of REE in this area caused by the inability of ZrO2 to accept larger amounts of the REE. The mechanisms of the Tb→Yb energy transfer vary between different phases of the GC. The results obtained in this study are important for the development of spectral down-converters for potential solar energy applications based on Tb-Yb co-doped glass-ceramics.

Nano-Structured Optical Fibers Made of Glass-Ceramics, and Phase Separated and Metallic Particle-Containing Glasses

“…Raman scattering can be also applied to characterize the phase-separated glasses, where sizes of the structures can be well below 100 nm. However, no information about the spatial distribution of the phases can be obtained in this case [103,104].…”

“…Fluorescence spectroscopy can reach a sub-micron resolution if a confocal microscope is used for the measurement, allowing one to follow the changes in the optical properties between different phases in the PCGs, especially in the GCs. Similarities in the equipment needed for the Raman and photoluminescence spectroscopies make it possible to use a Raman confocal microscope to measure both the structural and the emission properties in the same area with high spatial resolution [104]. In this case, the type of signal depends on the wavelength of the excitation laser ( Figure 2).…”

Impact of ZnO Addition on Er3+ Near-Infrared Emission, the Formation of Ag Nanoparticles, and the Crystallization of Sodium Fluorophosphate Glass

“…The other materials which can exhibit enhanced optical properties (such as absorption and emission cross-section and energy transfer rates) compared to glass are glass-ceramics (GCs). The enhancement of the spectroscopic properties can be achieved if the rare-earth ions are located around the crystalline phase [21,22]. Therefore, glass-ceramics have been intensively studied as they combine the merits of crystals and glasses [23][24][25].…”