Influence of vanadium oxide on the structural, optical, mechanical and dielectric properties of cadmium borate glasses

The melt-quenching method has been employed to fabricate 30B₂O₃-(70-x)CdO-xV₂O₅; x = 0, 1, 2, 3, and 5 mol% glasses. The physical, optical, mechanical, and dielectric properties of the prepared glasses were measured. Structural FTIR spectra and their related deconvolution process showed distinct absorption bands, from which some parameters especially, the N₄ ratio, could be determined by calculating the area under peaks. The successive addition of V₂O₅ up to 2 mol% at the expense of CdO in the glass network led to an increase in density from 4.27 to 4.69 g/cm³ for the prepared glasses while adding more V₂O₅ led to a decrease in density. The molar volume showed the same trend that occurred in the density, but in an opposite direction, as it decreased by increasing V₂O₅ content till the 2 mol% samples, then increased. The optical energy gap values (Eg) were calculated and were found to decrease from 2.95 to 1.35 eV with increasing levels of V₂O₅. With varying V₂O₅ concentrations, the mechanical characteristics of cadmium borate glasses increased up to 2%, declined at 3%, and then improved once again at mol%. The maximum microhardness, fracture toughness, and Young's modulus were 624.12 HV, 2.87 MPa.m^0.5, and 63.71 GPa for samples contained 2 mol% V₂O₅ which improved about 14.91, 32.26, and 21.84% compared to unreinforced glass sample. In addition, adding V₂O₅ and increasing the frequency had a positive effect on the electrical conductivity with the real and imaginary dielectric constant, and tan δ is the opposite. The electrical conductivity and tan δ of glass containing high V₂O₅ at a frequency of 20 MHz were 1.45 × 10⁻² S/cm and 0.0619, respectively, at a frequency of 20 mΩ.