Preparation And Electrical Properties Of PbZrO₃ Based Antiferroelectric Thin Films

Dielectric capacitors composed of dielectric materials have received widespread attention for their high power density and fast charge/discharge characteristics,and have potential applications in pulsed power systems.Antiferroelectric PbZrO₃（PZO）,as a typical dielectric material,has a relatively high energy storage density due to its unique electric field-induced phase transition characteristics,and has a wide range of applications in the field of microelectronic device and electrical engineering.The current preparation methods of PZO antiferroelectric thin films include chemical solution deposition（CSD）,pulsed laser deposition（PLD）,magnetron sputtering,etc.,and each preparation method has its own advantages and disadvantages.Therefore,the preparation of PZO antiferroelectric films with excellent electrical properties is very important for both research and applications.In this thesis,PZO-AO nanocomposite thin films,which are aluminum-rich nanoparticles（AO）distributed in PbZrO₃matrix,and PbZrO₃-PbTiO₃（PZO-PTO）nanocomposite films,which are PTO nanoparticles distributed in PZO matrix,were prepared by a sol-gel method.The effects of the preparation methods on the microstructure,electrical properties,and energy storage properties were systematically investigated.The main research contents and results are as follows.1)By self-diffusion,the antiferroelectric nanocomposite thin films that Al-rich（AO）nanoparticles distribute uniformly in the PbZrO₃（PZO）matrix were obtained.Compared with PZO films,the PZO-AO nanocomposite thin films increase breakdown strength and recoverable energy storage density by 181%and 66%,respectively.By analyzing the conduction mechanism of the thin film,the reasons for its performance improvement are discussed.2)The effect of AO content on the microstructure and electrical properties of PZO-AO composite films was systematically studied by changing the deposition thickness of Al layer and controlling the volume fraction of AO and PZO.When the AO content is greater than 1 Vol%,the composite film gradually changes from antiferroelectric to ferroelectric,and the ferroelectric residual polarization can reach nearly 40μC/cm².3)The amorphous PZO-PTO composite films were prepared by adding gel PTO powders to the PZO precursor solution using a sol-gel method,and then,they were heated in a muffle furnace to crystallize them to the perovskite phase,and the microstructure and electrical properties of the PZO-PTO composite films were investigated.The results show that the electrical properties of the composite films gradually changed from antiferroelectricity to ferroelectricity with the increase of PTO addition,and this simple method provides a new idea for regulating the ferroelectric properties of PZO films.