Novel Multicomponent Titanate-Germanate Glasses: Synthesis, Structure, Properties, Transition Metal, and Rare Earth Doping

Wojciech A Pisarski,Marta Kuwik,Karolina Kowalska,Justyna Polak,Ewa Pietrasik,Joanna Pisarska,Tomasz Goryczka

doi:10.3390/ma13194422

Abstract

Novel multicomponent titanate-germanate glasses singly doped with transition metal (Cr3+) and rare earth ions (Eu3+) were synthesized and the glass transition temperatures and thermal stability parameters were determined using DSC measurements. X-ray diffraction analysis confirmed fully amorphous nature of the received samples. Their structural and optical properties were compared with germanate glasses without TiO2. Correlation between local structure and optical properties in titanate-germanate glasses is well evidenced by FT-IR, Raman, EPR, and luminescence spectroscopy. In particular, luminescence spectra and their decays are examined for glass samples, where GeO2 was partially substituted by TiO2.

Highlights

Since 1986 the formation of TiO2 containing glasses has been investigated in detail [1,2,3,4,5,6,7,8].most of titanate glass systems are partly crystallized
Any significant structural changes in the X-ray diffraction (XRD) patterns have been observed for glass samples after transition metal (TiGe-Cr) or rare earth (TiGe-Eu) doping
It clearly indicates that titanate-germanate glasses are able to accommodate transition metal or rare earth ions and the samples are still fully amorphous

Summary

Introduction

Most of titanate glass systems are partly crystallized. The obtained systems possess crystalline phases mainly because of different titanates and their thermal stability parameters are relatively low, which makes them unsuitable for optical-fiber applications. Germanate glasses have quite strong chemical and mechanical stability useful for optical fiber drawing and belong to low-phonon glass family. Compared to other low-phonon glass systems such as tellurite glasses, germanate based glass-host matrices have relatively large glass-forming region. Thermal stability parameter referred to as a difference between crystallization onset Tx and glass transition temperature Tg is considerably higher for germanate-based glass with ∆T = 155 ◦ C [9] than tellurite based glass with ∆T = 27 ◦ C [10].

Methods

Results

Conclusion