The effects of SiO2 (amorphous) and TiO2 (crystalline, rutile) fillers on softening point (𝑇s), glass transition temperature (𝑇g), coefficient of thermal expansion (CTE), and dielectric constant (𝜀) of zinc bismuth borate, ZnO–Bi2O3–B2O3 (ZBIB) glass microcomposites have been investigated with a view to its use as the white back (rear glass dielectric layer) of plasma display panels (PDPs). The experimentally measured properties have also been compared with those of theoretically predicted values. Both the experimental and theoretical trends of these properties with added filler contents correlate very well. The interaction of fillers with glass which occurred during sintering at 560°C has also been monitored by XRD and FTIR spectroscopic analyses. The microstructures and distribution of fillers in the glass matrix have been analyzed by SEM images. It is observed that the fillers have partially dissolved in the glass at the firing temperature leaving some unreacted filler as residue which results in ceramic–glass microcomposites. In consideration of the desired properties of white back of PDPs, the addition of TiO2 filler to ZBIB glass is found to be more preferable than SiO2 filler. The addition of 10 wt% TiO2 filler yielded 𝑇s, 𝑇g, CTE and 𝜀 values of 560°C, 480°C, 82 × 10-7/K and 14.6 which are found to meet the desired values of < 580°C, < 500°C, < 83 × 10-7/K and < 15, respectively with respect to use of PD200 glass as substrate in PDP technology.
Volume 42 | Issue 6
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