Barium strontium titanate (BST) glass-ceramics were fabricated via controlled crystallization with different crystallization routes. Effects of the microwave crystallization and microwave treatment on the microstructure and energy storage properties of the glass-ceramics were systematically investigated. Results showed that microwave crystallization can increase the dielectric constant. In addition, it was found that the microwave process had little impact on the crystallinity (about 90 wt%), but preferred the crystallization of SrAl4O7. Most importantly, the dielectric breakdown strength (BDS) of the glass ceramics was significantly improved from 561.3 to 791.4 kV/cm by the microwave crystallization. And it can be further enhanced to 900.0 kV/cm by conventional crystallization combined with microwave treatment. The corresponding energy densities of samples derived from the microwave processes were increased to 1.05 and 1.13 J/cm3, respectively, compared with the sample fabricated by the conventional crystallization route (0.47 J/cm3).

Ferroelectric film-on-foil capacitors hold special promise to replace discrete passive components in the development of electronic devices that require greater performance and smaller size. We have deposited Pb0.92La0.08Zr0.52Ti0.48O3 (PLZT) films on base metal foils to form film-on-foil capacitor sheets that can be embedded into printed circuit boards. The rootmean-square surface roughness was determined to be ≍3 nm for 1.15-μm-thick PLZT films on LaNiO3-buffered Ni foils. The following dielectric properties were measured: relative permittivity of ≍1300 and dielectric loss (tan δ) of ≍0.05, leakage current density of 6.6 × 10−9 A/cm2 at 25°C and 1.4 × 10−8 A/cm2 at 150°C, and mean breakdown strength >2.5 MV/cm. A remnant polarization (Pr) of ≍33 μC/cm2 and coercive field strength (Ec) of ≍50 kV/cm were observed with a maximum voltage of 300 V applied during the P-E loop measurement. The energy storage capability of the dielectric film is ≍45 J/cm3.