Effect of gas environment on the properties of silver-glass composite powders with core-shell structure prepared by spray pyrolysis

Silver-glass composite powders were directly prepared by using spray pyrolysis in various gas environments. The composite powders with a core-shell structure and a crystal structure of silver had a spherical shape and submicron size irrespective of the gas environments. The silver conducting thick films formed from the composite powders prepared using spray pyrolysis in air and Ar environments had dense structures and low pore volumes at firing temperatures of 450 and 500 °C. In contrast, the thick films formed from the composite powders prepared by spray pyrolysis in a reducing environment by applying H₂/N₂ or H₂/Ar mixture gases had porous structures. The silver conducting thick films formed from the composite powders prepared in air and Ar atmospheres had low specific resistances of 3 and 3.2 μΩ cm at a firing temperature of 450 °C. In contrast, the silver conducting thick films formed from the composite powders prepared in N₂ and reducing atmospheres had specific resistances of more than 4 μΩ cm at a firing temperature of 450 °C. The silver conducting thick films formed from the composite powders prepared in air, N₂, and Ar atmospheres had low specific resistances of 2.7, 2.1, and 1.8 μΩ cm at a firing temperature of 500 °C.