Characteristics of BaTiO₃-coated Ag powders directly prepared by spray pyrolysis

Spherical BaTiO₃-coated Ag powders with dense structures were directly prepared by spray pyrolysis. Ag powder with 1wt% BaTiO₃ has particles of 0.53μm mean diameter. BaTiO₃ had good properties for coating Ag powders: it decreased the sintering of the Ag powder at temperatures between 700 and 900°C. Complete melting of pure Ag powder, forming dense Ag thick film, occurred at 700°C. Whereas at this temperature, partial melting of the 1wt% BaTiO₃-coated Ag powder occurred, forming Ag thick film with a porous structure. The pure Ag thick film shrunk 45% at 900°C. However, the thick films formed from 1 and 5wt% BaTiO₃-coated Ag powder had respective shrinkages of 31 and 21%, respectively at 900°C. The sheet resistances of the Ag thick films formed from the 1wt% BaTiO ₃-coated Ag powder were 7.54, 4.93 and 4.09mΩ/sq at firing temperatures of 700, 800 and 900°C, respectively.