Dielectric properties of manganese-doped TiO2 with different alkali-free glass contents for energy storage application

The dielectric properties and microstructures of 0.05 mol% manganese (Mn)-doped TiO2 with different alkali-free glass (BaO-B2O3-Al2O3-SiO2) contents were investigated. The alkali-free glass which coated Mn-doped TiO2 ceramic powders was prepared by sol-gel method, all samples were sintered at 1100 A degrees C for 6 h. Microstructure observation indicated that the grain size greatly reduced and microstructure uniformity was improved by adding 15 wt% alkali-free glass. The alkali-free glass did not only decrease the dielectric loss (< 0.01), but also significantly enhanced the frequency/temperature stability of dielectric properties. The energy density of 15 wt% glass-ceramics could achieve 1.15 J/cc with average breakdown electric field (E-b) of 50.17 kV/mm, the polarization-electric field (P-E) hysteresis loops showed that glass-ceramic composites had a very low energy loss.