Effects of Glass Structure on the Optical Absorption of Transition Ions in Industrial Soda-Lime-Silica Glasses

Abstract

The optical absorption due to Mn 3+ , Cu 2+ , Ni 2+ and Co 2+ ions in industrial soda-lime-silica glass was investigated as a function of the Na 2 O concentration in the range of 11-19 mol%. With increasing Na 2 O concentration in the experimental glasses, the calculated basicity; Λ cal , increased. The 29 Si NMR spectra showed a high proportion of non-bridging oxygens; NBOs as the basicity of glass was increased. The results are thought to be due to tetrahedral networks; Q 4 species were disconnected by replacing the bridging oxygens; BOs with NBOs forming Q 3 species. These results were confirmed by a shift and broadening of XRD peaks. The redox reactions of the Mn 2+-Mn 3+ and Cu +-Cu 2+ couples shifted toward the more oxidized ions due to oxygen partial pressure; p(O 2) during melting and the oxide ion activity; a O2-where increase with increasing glass basicity. While the Ni 2+-Ni 3+ and Co 2+-Co 3+ couples were assumed to be presented only the Ni 2+ and Co 2+ ions in these glasses, respectively. The optical absorption bands due to Mn 3+ , Cu 2+ , Ni 2+ and Co 2+ ions occurred at characteristic wavelengths with different optical densities or intensities as a function of glass basicity. The increase in the intensities of the absorption bands of these absorbing ions depended not only on the ion concentration but also on the increase of polarisability of the oxide (-II) species; α oxide(-II) surrounding the ions. This value directly affected the extinction coefficients of the ions; ε ion. The increase of ε ion is associated with increased intensity of color.

Structural and vibrational characterization of medieval like glass samples

“…The characteristic large band of the reproduced glasses are shifted at higher 2θ angles with respect to the value of 21.5°found for the pure amorphous silica, where all the SiO 4 tetrahedra are connected through bridging oxygens (BO) (presence of only Q 4 units) [44][45][46][47][48]. Even if the exact relationship between the peak position and MRO is still widely debated in literature [40][41][42][43], the 2θ increase with potassium content (Fig.…”

Electron and hole capture processes in Cu-doped glass exhibiting radiophotoluminescence

“…In the spectrum of the Cudoped ABS glass, a strong absorption indicated as a shoulder at approximately 5.2 eV and a weak absorption at 1.7 eV, as shown in the inset of figure 1, were observed. The former was assigned to the transition from 3d 10 to 3d 9 4s 1 of Cu + ions and the charge transfer transition from O 2− to Cu 2+ ions, while the latter was due to the d-d transition of Cu 2+ ions [36,37,[39][40][41]. We estimated the molar absorption coefficient of the d-d transition of Cu 2+ from the optical basicity of the glass to be 26.9 l mol −1 cm −1 [41].…”

“…The former was assigned to the transition from 3d 10 to 3d 9 4s 1 of Cu + ions and the charge transfer transition from O 2− to Cu 2+ ions, while the latter was due to the d-d transition of Cu 2+ ions [36,37,[39][40][41]. We estimated the molar absorption coefficient of the d-d transition of Cu 2+ from the optical basicity of the glass to be 26.9 l mol −1 cm −1 [41]. Using this value and the absorption intensity at 1.7 eV, the Cu 2+ concentration was calculated to be 0.97 × 10 18 atoms/cm 3 , and the fraction of Cu 2+ to the total copper concentration was estimated to be approximately 95% in this glass.…”