Titanium in normal melting conditions in air atmosphere present as Ti⁴⁺ ion in basic silicate glasses exhibited an ultra-violet cut-off in silicate glasses, viz. soda–magnesia–silica, soda–magnesia–lime–silica and soda–lime–silica glasses. This indicates that Ti⁴⁺ ion can be a good replacement for Ce⁴⁺ ion in producing UV-absorbing silicate glasses for commercial applications. The wavelength maxima at which the infinite absorption takes place in glasses was found to be around 310 nm against Ti-free blank glass in UV-region. The mechanism of electronic transition from O^2- ligands to Ti⁴⁺ ion was suggested as L $\rightarrow$ M charge transfer. The low energy tails of the ultra-violet cut-off were found to obey Urbach’s rule in the optical range 360–500 nm. The fluorescence spectra of these glasses were also studied and based on the radiative fluorescent properties it was suggested that the soda–lime–silica glass containing Ti⁴⁺ ion with greater emission crosssection would emit a better fluorescence than the corresponding soda–magnesia–lime–silica and soda–magnesia–silica glasses. The shift of emission wavelengths maxima towards longer wavelength in titania introduced silicate glasses was observed on replacement of MgO by CaO which may be attributed due to an increase in basicity of the glass system.

Absorption characteristics of Cu²⁺, Mn³⁺ and Cr³⁺ ions in ternary silicate (20Na₂O.10RO.70SiO₂, where R=Ca, Sr, Ba) glasses were investigated. The intensities of absorption bands due to Cu²⁺ ion was found to increase with increasing ionic radii of the alkaline earth ions whereas it was found to decrease in case of Mn³⁺ and Cr³⁺ ions with increasing ionic radii of the alkaline earth ions. The results were discussed in the light of relation between linear extinction coefficients of these ions and coulombic force of alkaline earth ions. The change in intensities of Cu²⁺, Mn³⁺ and Cr³⁺ ion is attributed due to change in silicate glass compositions.

The role of tin as a reducing agent in a 18Na₂O.2MgO.8CaO.72SiO₂ glass containing a definite amount of total, 𝛴 Fe = [Fe²⁺] + [Fe³⁺], was investigated with different concentrations of total tin, 𝛴 Sn = [Sn²⁺] + [Sn⁴⁺], by absorption spectra of iron ions in the optical range 300–1200 nm recorded on a JASCO-7800 spectrophotometer. The single broad absorption band for Fe²⁺ ion was marked at 1055 nm in the near infrared region and a narrow weak band for Fe³⁺ ion at its 𝜆_max at around 380 nm was observed in the silicate glass. The proportion of ferrous iron was found to increase in the glass in the beginning with the addition of tin up to 0.788% 𝛴 Sn and then it approached a maxima with 1.182% 𝛴 Sn. Further addition of tin was found to be futile for the constant iron concentration of 0.875% for achieving higher [Fe²⁺]/[Fe³⁺] ratio for maximum heat absorption due to Fe²⁺ ion in the glass. The mechanism of the process was discussed on the basis of Sn²⁺/Sn⁴⁺ and Fe²⁺/Fe³⁺ mutual redox interaction in the molten glass at 1400°C. The suitable limit of tin was suggested to be 0.788 ≤ 𝑥 ≤ 1.182% by wt for 0.875% of total iron for getting maximum ferrous ion in the glass.

A complete range of indium-doped (In:SnO$_2$) thin films prepared by spray-pyrolysis technique have been studied and characterized by different techniques to get information about structure, surface and electrical properties. The influence of indium filler concentration (i.e., 0–15 wt%) on the properties of SnO$_2$ has been explored. Structural study reveals that the inclusion of indium after a certain optimum value leads structural distortion which causes the films’ expansion along c-axis direction. The extract of electrical study helps to understand that what should be the optimum value to switch from n- to p-type, which is further confirmed by Hall measurement. A deep analysis of electrical data confirms that the solid solution of indium into SnO$_2$ should not be completely excluded and its range should not be >12 wt% as we got saturation in the electrical behaviour after it. Variable range hopping mechanism has been found to be best fitted for low temperature range and comes out with valuable information that increase in density of states near Fermi level are responsible for decrease in resistivity in case of higher doping and also confirms that 6 wt% is the optimum value to switch from n- to p-type conductivity.