Preparation And Electrical Properties Of Platinum-Lead Zirconate Titanate Nanocomposite Films

Lead zirconate?Pb?Zr,Ti?O₃?ferroelectric thin films has been widely used in non-volatile memory,solar cell and high energy density capacitor due to its excellent ferroelectric and dielectric properties.The functional properties of these materials are generally achieved by electrical polarization reversal.Thus,how to improve its ferroelectric properties has become a hot research topic.In this paper,Pt-Pb(Zr_0.52Ti_0.48)O₃?Pt-PZT?composite film was prepared by the combination of Pt metal particles and Pb(Zr_0.52Ti_0.48)O₃.In this paper,Pt-PZT nanocomposite films were successfully prepared by a sol-gel method,and the effects of Pt particles on the crystal structure,microstructure,ferroelectric and dielectric properties of Pt-PZT nanocomposite films were studied.The results showed that Pt particles with a particle size of about 5 nm existed in the Pt-PZT nanocomposite films in the form of elemental form.When the Pt concentration was 1.2mol%,the remanent polarization value could reach 47?C/cm²,which was 42.4%higher than that of the pure PZT film.Meanwhile,the dielectric constant was also 120%higher,indicating that the ferroelectric property of the film could be significantly improved by adding an appropriate amount of Pt nanoparticles.The effects of Pt nanoparticles on the crystallization process of Pt-PZT nanocomposite films were studied by crystallizing amorphous Pt-PZT nanocomposite films at four different annealing temperatures.Combined with the study of crystallization kinetics and experimental characterization,it was found that the calculated Avrami coefficient n value was about 0.85,indicating that the crystallization process of the composite film was controlled by grain growth,and the crystal core grew along the direction of the film thickness in one dimension to form columnar grains.As heterogeneous nucleation points,Pt particles promoted the nucleation crystallization of PZT,and the crystallization activation energy was reduced to 176 KJ/mol,which was much lower than that of PZT film.Thus,the promoting role of Pt in the crystallization process of Pt-PZT nanocomposite film was determined.Layered Pt-PZT nanocomposite films with sandwich structure were successfully prepared by using the Pt layer as the intermediate layer intercalated into the PZT layers.The effects of the concentration of Pt in the intermediate layer on the preparation and properties of Pt-PZT nanocomposite films were investigated.Results showed that when the concentrations of Pt is0.01mol/L,the layered sandwich structure in the Pt-PZT composite film is clearly visible,and the PZT grains were columnar,showing Pt particle layer to further promote the PZT columnar grain growth.For local electric field can be formed and enhaced by Pt particle layer intercalating into PZT films,the remanent polarization value of the layered Pt-PZT composite films is significantly higher than that of pure PZT film.These results indicate that adding Pt nanoparticles is an effective method to improve the ferroelectric properties of PZT.