Crystallization And Energy Storage Performance Of PbZrO₃ Thin Films In Microwave Magnetic Field

Dielectric capacitors made of dielectric materials have attracted wide attention because of their high power density and rapid charge-discharge characteristics and have potential application prospects in pulsed power systems.As a typical dielectric material,Pb Zr O3(PZO)-based antiferroelectric materials have been widely studied and used for energy storage due to their high energy storage density during the electric field induced antiferroelectric-ferroelectric phase transition.Compared with bulk ceramics,antiferroelectric films can obtain a higher energy storage density at a higher electric breakdown field.At present,the deposition techniques of PZO antiferroelectric thin films include chemical solution deposition,pulsed laser deposition,magnetron sputtering,and each method has its own advantages and disadvantages.Therefore,it is very important to study the preparation method of PZO antiferroelectric films to obtain excellent energy storage performance.In this thesis,amorphous PZO films were prepared by a sol-gel method,and the films were crystallized by microwave irradiation.The effects of microwave irradiation on the crystallization behavior,microstructure,electrical properties and energy storage performance of antiferroelectric film were studied.The main research contents and results are as follows:Amorphous PZO films were deposited on Pt/Ti/SiO2/Si substrates by the sol-gel method,and then crystallized by microwave irradiation.The microstructure,electrical properties and energy storage performance of PZO films were studied.The results show that the PZO films crystallized by microwave irradiation have a compact microstructure and show a highly(100)-preferred orientation.The energy storage density of PZO films crystallized by microwave irradiation is 14.8 J/cm~3 at 740 k V/cm,which is 40%higher than that of PZO films crystallized by conventional annealing.Amorphous PZO films were deposited on Pt/Ti/SiO2/Si substrates by the sol-gel method,and then crystallized by microwave irradiation.The crystallization process and crystallization kinetics of PZO films were studied.The results show that perovskite PZO films can be crystallized by microwave irradiation at a low temperature or in a short time.The effective activation energy for crystallization process by microwave irradiation and conventional annealing are 121 k J/mol and 274 k J/mol,respectively,indicating that microwave irradiation can reduce the effective activation energy for crystallization of perovskite phase.At the early stage of crystallization,there is a(100)-Pb O intermediate phase at the PZO/Pt interface,which makes the perovskite PZO show a(100)preferred orientation.Amorphous PZO films were prepared by the sol-gel method on the La NiO3(LNO)electrode layer,and then crystallized by microwave irradiation.The microstructure,electrical properties and energy storage performance of PZO films were investigated.The results show that the perovskite phase PZO films with a uniform grain size and compact microstructure can be obtained by microwave irradiation at 750°C in only 180 s.At 1640 k V/cm,the energy storage density of PZO films can reach 27.3 J/cm~3,and the energy storage efficiency is 59%,which show a good energy storage performance.