Spectroscopic studies of chromium doped alkali earth lead zinc phosphate glasses

Abstract

X-Ray diffraction, energy dispersive X-ray, Fourier transform infrared, Raman spectroscopy, differential scanning calorimetry, UV–Visible spectroscopy and electron paramagnetic resonance spectroscopic studies have been carried out on alkali earth lead zinc phosphate glasses doped with 0.1 % chromium ions. The energy dispersive X-ray spectra reveal fundamental compositional information of the glasses. Infrared spectra indicate that phosphate network is depolymerized with progressive substitution of alkali earth content and inform the characteristic vibrations of PO4 3− units. Raman spectra suggest that these glasses are consisting of metaphosphate [Q2] units along with some bands related to pyrophosphate [Q1] and orthophosphate [Q0] units. The crystal-field parameter and inter-electronic repulsion parameters have been evaluated from optical absorption spectral data. Electron spin resonance spectra of Cr3+ systems indicate that g ∥ > g ⊥ and Cr3+ ions are located at sites with lower symmetry. It is obtained that the glass transition temperatures fall in region of 377–360 °C. Increase in density of the glass system brings changes in structure of the glasses on replacement of alkali earth content.