Effect of limited current on ultrarapid densification and giant dielectric properties of flash sintering (La, Ta) co-doped TiO2 ceramics

Flash sintering is considered a promising energy-saving and efficient technology for preparing high-temperature ceramics. The effects of limited current on flash sintering parameters, microstructure, and electrical properties of (La1/2, Ta1/2)0.02Ti0.98O2 ceramic were investigated by the XRD, SEM, XPS, and precision impedance analyzer. With limiting current increase, the grain size of flash sintering sample increases gradually, and the relative density increases first and then decreases. The average grain size is about 1 μm, and the highest relative density is 96.9