Structural, thermal, and DC conductivity properties of WO3–P2O5 glasses doped with B2O3

Abstract

In this study, glasses in composition 70WO₃–(30 − х)P₂O₅–хB₂O₃ (0 ≤ х ≤ 20 mol%) were prepared by melt quenching method. The glass formation, structure, and thermal and electrical properties are discussed. Homogeneous glasses were obtained at x = 0–10 mol% B₂O₃, whereas glasses with x = 15 and 20 contain microinclusions of WO₃. The glass transition temperature decreases from 709 to 531.6°C with increasing B₂O₃ content, as well as the crystallization temperature and the thermal stability. The structure of the glasses was studied by Raman spectroscopy and infrared spectroscopy. The Raman spectra are characterized by a band near 995 cm⁻¹, a broad band at 788–800 cm⁻¹, and a band near 675 cm⁻¹ ascribed to vibrations of W–O–P, W–O–W, and P–O–B bonds, respectively. The Fourier-transform infrared spectra show vibrational bands due to characteristic phosphate and borate groups. Tetrahedral BO₄ units prevail in the structural network. The electrical conductivity of the glasses decreased with x content due to the growth of WO₃-deficient regions.