Sm2O3 modulated structural, optical, thermal and electrical properties of LiBaBO3 glasses

Abstract

Structural, optical, thermal and electrical properties of (1-x)[50B₂O₃–30Li₂O–20BaO]-xSm₂O₃ glasses [where x=0, 0.2, 0.4, 0.6, 0.8 and 1.0 mol%], synthesized by using a traditional melt-quenching technique, are reported in this paper. XRD, SEM/EDX studies on these glasses confirm the glassy structure and also their elemental composition. The densities of the samples, declined from 3.094 to 3.045 g/cm³, as the concentration of the dopant Sm₂O₃ increased, while the molar volume increased from 24.059 to 24.986 cm³/mol. FTIR, Raman spectra and UV–Vis spectra of these glasses to determine their optical characteristics. The direct and indirect band gap energies of the glass samples varied in the ranges of 3.99–3.74 eV and 3.01–2.71 eV, respectively. A decline in the Urbach energy from 0.43 to 0.32 eV is observed with increase of the dopant. The obtained results are discussed with reference to the structural changes in the glass network. The glass transition temperature increased by increasing the dopant concentration and the heating rate according to the DSC analysis of the formed glasses. The activation energy of the glass transition also increased with the dopant concentration. The variation of the DC conductivity with temperature was studied to understand electronic transport phenomena in these glasses.