Vanadyl doped Li-zinc borate glasses: Optical and ESR study

Glasses with the composition xV2O5-(15-x) Li2O-70B2O3-15ZnO, for x varies from 0 to 4 mol. %, were synthesized using standard quenching technique. The amorphous nature for selected samples (x= 0, 1 and 4 mol. %) was ensured from X-ray diffraction (XRD) measurements. The samples were found to compose mainly from BO3 and BO4 basic structural units as inferred from Fourier transform infrared (FTIR) data. The number of BO4 (BO3) structural units was found to decrease (increase) with increasing the number of NBOs. These structural modifications within the glass network are responsible for the here observed composition dependence optical energy gap (Eotp) and Urbach band tail (Delta E). The electron spin resonance (ESR) results revealed a tetragonal compression for VO2+ ions present in octahedral coordination, with distinct optical transitions in the visible spectral regime.

Automated summary

The structural modifications within the glass network were found to be responsible for the observed changes in optical energy gap and Urbach band tail. The electron spin resonance results revealed distinct optical transitions in the visible spectral regime.