Microstructures, phases, and properties of low melting BaO–B2O3–ZnO glass films prepared by pulsed laser deposition

• Glass transition temperature and crystallization temperature of the films are ~ 536 and 640 °C, respectively.
• The maximum dielectric constant for the heat treated film is 14.3.
• Zn concentration is reduced after heat-treatment at high temperature.
• The phases are quite complicated for the films heat-treated between 700 and 800 °C.
• 700 °C is the optimal temperature to use BaO–B2O3–ZnO glass for high performance capacitors.

With the motivation to employ BaO–B2O3–ZnO for high performance capacitors by using viscous flow/liquid phase sintering, the microstructures, phases, and dielectric properties of BaO–B2O3–ZnO films prepared by pulsed laser deposition were examined as a function of heat-treatment. The glass transition temperature (Tg) and crystallization temperature of the films are ~ 536 °C and 640 °C, respectively. The phases in the films are quite complicated after heat-treated above 700 °C until 900 °C where the film is dominated by a single phase. Zn concentration is reduced after heat-treatment at high temperature due to segregation and evaporation. The dielectric constant of the film decreases with the increasing heat-treatment temperature, probably due to Zn reduction, Si diffusion, and crystallization of the film. Experimental data shows that ~ 700 °C is the optimal temperature to use the low melting glass BaO–B2O3–ZnO to make high performance capacitors by viscous flow/liquid phase sintering.