Analysis of Interaction between RuO2 and Glass by Growth of RuO2 Particles in Glasses *

The RuO₂-glass interaction has been studied by analyzing the growth of RuO₂ particles in glasses. The size of RuO₂ particles was determined by TEM and X-ray line broadening. The RuO₂/glass interfacial energy was evaluated by spreading and penetration experiments.

Changes in size and shape of RuO₂ particles indicated that coarsening proceeded by the diffusion-controlled dissolution-precipitation process. The growth rate of RuO₂ particles at temperatures giving the same viscosity was dependent on the glass composition. Kinetics of the Ostwald ripening and values of glass surface energy implied that the solubility of RuO₂ in glass is a critical factor. Results indicated that the solubility of RuO₂ in glass decreases with increasing PbO content and with increasing SiO₂ substitution for B₂O₃. Dissolution of A1₂O₃ from substrate retarded the Ostwald ripening.