Study of Tungsten Phosphate Glasses Containing Fe<sub>2</sub>O<sub>3</sub>

Abstract

Glasses of the compositions 20Li 2 O-(50 − x)Li 2 WO 4 -xFe 2 O 3 -30P 2 O 5 where (x = 0, 1, 5, 8, 10, 15 mol%) were elaborated by the melt-quenching route. Synthesized glasses are characterized using X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), differential scanning calorimetric (DSC), and density determination. The XRD patterns confirmed the amorphous nature of samples, and IR spectra showed the structural groups and highlight the depolymerization of phosphate network with the introduction of iron oxide. It is found that the structural unit Q 2 converts to Q 1 and Q 0 as Fe 2 O 3 replaces Li 2 WO 4 . Chemical durability tests on the glasses have shown that the compositions containing pyrophosphate (Q 1 ) and orthophosphate (Q 0 ) units are more water-resist. The electrical conductivity measurements were performed by complex impedance spectroscopy in the frequency range of 20 -10 6 Hz at various temperatures from ambient to 400˚C. It is found that the conductivity is activated thermally and follows an Arrhenius law. The obtained electrical data were analyzed by the modulus formalism and dielectric formalism. The determined asymmetric nature of max M M ′′ ′′ spectra suggested that the relaxation behavior is non-Debye and characterized by the stretched exponent parameter β < 1.

Investigation DSC and XRD on the crystallization kinetics in the phosphate Li2O–Li2WO4–TiO2–P2O5 glassy ionic system

“…When the chains are completely surrounded by water, they can separate from the partially hydrated chains and dissolve in solution. Once the hydrated layer is constant, the dissolution is linear over time [28].…”

Investigation DSC and XRD on the Crystallization Kinetics in the Phosphate Li2O−Li2WO4−TiO2−P2O5 Glassy Ionic System

“…When the chains are completely surrounded by water, they can separate from the partially hydrated chains and dissolve in solution. Once the hydrated layer is constant, the dissolution is linear over time [28]. Figure 2 represents the evolution of the weight loss at the initial surface (g.cm -2 ) of the glass as a function of time (h).…”