Cogency of chromium ions in strengthening spectroscopic and dielectric properties of B2O3-Bi2O3-Al2O3-MgO glass materials

Abstract

The multi-functional glasses 65B₂O₃-20Bi₂O₃-10Al₂O₃-(5-x)MgO: xCr₂O₃ (0 ≤ x ≤ 0.5 mol%) were prepared by conventional melt quenching and heat treatment process. The samples were explored by examining X-ray diffraction (XRD), Fourier transform infrared (FTIR), Raman spectra, electron spin resonance spectra (ESR), emission spectra, optical absorption, and dielectric studies. The physical, optical, and dielectric properties of samples were investigated. The highest concentration of chromium ions is 9.845 X 10²¹ ions/cm³ for the glass doped with 0.5 mol% of Cr₂O₃. The studies on FTIR and Raman spectra reveal the structural changes in glasses by exhibiting an in increase in intensity of the bands due to BO₃ units. ESR spectra of doped glasses displayed an intense resonance signal at g = 4.20 due to Cr³⁺ ions. The emission spectra of glasses exhibited a sharp peak centered at 740 nm due to ⁴T_2g → ⁴A_2g transitions of Cr³⁺ ions. The optical absorption spectra of glasses displayed an intense absorption band centered at 615 nm. The least values of direct and indirect optical bandgap of glasses are 2.687 and 2.364 eV, respectively. Dielectric properties were investigated on a temperature scale of 30–300 °C by varying frequencies in the range of 10³–10⁶ Hz to ascertain the suitability of glasses for various electronic and laboratory applications. The estimated maximum a.c. conductivity for a glass doped with 0.5 mol% of Cr₂O₃ is 5.86 X 10^–6 (Ω-cm)⁻¹. The glass doped with 0.5 mol% of Cr₂O₃ was perceived as the suitable material for diverse optical and dielectric applications.