Spectroscopic and dielectric studies on PbO-MoO3-B2O3 glasses incorporating small concentrations of TiO2

摘要

This paper deals with the investigation of a variety of physical properties including dielectric constant ( over a wide range of frequency and temperature), optical absorption, luminescence, electron spin resonance ( ESR) and infrared spectra of a TiO2-doped lead molybdenum borate glass system. The composition chosen for the study is 30PbO-4MoO(3)-(66-x)B2O3:xTiO(2) (with x ranging from 0.2 to 2.0). Quantitative analysis of the results of this study shows that, when the content of TiO2 is around 0.8 mol%, the titanium ions exist predominantly in the tetravalent state and occupy substitutional positions in the glass network. A substantial increase in the insulating strength of these glasses on TiO2 doping has also been observed. When the concentration of TiO2 is increased beyond 0.8 mol%, it is observed that titanium ions exist primarily in the Ti3+ state and molybdenum ions in the Mo5+ state; analysis of the results further suggests that both of these ions participate in the depolymerization of the glass network.