Giant dielectric constant and tunable phase‐transition characteristics of ZnF₂/BaF₂‐modified BaTiO₃ thick films

Abstract

High performance capacitors have been investigated to meet higher integration density with optimized charge-storing capability. Here, we introduce nonconventional thick film dielectric compositions based on 95BaTiO 3 -xZnF 2 -(2−x)BaF 2 -3glass (x = 0.5, 1.0, and 1.5) where the relative content of ZnF 2 /BaF 2 is critical in controlling dielectric behavior. The thick films were prepared on Cu foils by regular screen-printing and then firing at 950°C in inert atmosphere. As an optimal example, thick film composition modified with 1.0ZnF 2 /1.0BaF 2 exhibited a dielectric constant of~1903 and a dielectric loss of~0.04 at 1 MHz with dispersive dielectric relaxation behavior, which are far better than any reported corresponding values so far. Particularly, it was very interesting to observe that Curie temperature was tunable from −19 to +34°C, depending on the relative content of fluoride additives only within the 2 mol% range. Dependency of the relative contents of the fluorides is primarily investigated with regard to microstructure and dielectric properties. K E Y W O R D Sdielectric materials/