Optimization Of Properties For CaTiO₃ Ceramics

Dielectric capacitors are key energy storage components in pulsed power circuits and have a higher power density than other energy storage materials.CaTiO3,as one of the earliest discovered typical linear dielectric material with perovskite structure,has been widely used in high-frequency ceramic capacitor materials due to its unique physical properties and high relative permittivity and negative temperature coefficient.At the same time,the microstructures of dielectric materials shows great influence on their energy storage and dielectric properties.So,it's possible to optimize energy storage performance of CaTiO3 ceramics by regulating their microstructures.CaTiO3 nanoparticles are prepared by sol-gel method.Morphology control of CaTiO3 nanoparticles is realized by changing the concentration of precursors and calcination temperature.The CaTiO3 ceramic microstructure is regulated by adjusting the sintering time and temperature.Fine CaTiO3 ceramics are prepared with 0.5 times concentration of precursors,which is calcined at 700 ? and sintered at 1350? for 2 h.The relationship between morphology and dielectric strength,and the effect on the energy storage density of the ceramics are also investigated.At last,we improved the energy storage density of CaTiO3 ceramics.When the concentration of precursor reduced,the size of CaTiO3 particles is increased.And when the calcination temperature increased,the particle size of CaTiO3 is also increased.The density of ceramic is important for the dielectric strength and energy storage density.The higher the density of the ceramics,the higher the dielectric strength and density of energy storage.The best sintering point with the highest density of CaTiO3 ceramics is also corresponded to the largest dielectric strength.The best energy storage performance of ceramics prepared by conventional sintering is 5.20 J/cm3.With SPS technique,the average grain size of CaTiO3 ceramics is controlled under 1 ?m,result in an energy storage density of 3.16 J/cm3.The smaller the grain size and the higher the density of ceramics are,the larger dielectric strength and the higher,energy storage density are.