Preparation And Optical Property Of PZT Ferroelectric Thin Films/LaNiO₃ Thin Films Periodic Structure

Ferroelectric thin films with perovskite phase attract much attention not only because of their notable ferroelectric and electro-optic characteristics, but also their high dielectric constant. In recent years, this kind of material has been imported to the research of supedattice and photon crystal.It occurs some new changeable factors in the research of supedattice/photon crystal when ferroelectric thin films are embedded. Ferroelectric thin films have much higher dielectric constant than general materials, and have spontaneous polarization which can change with temperature and electric field, possess nonlinear optics characteristic.The main work of this thesis is to fabricate[PZT/LNO]~n multilayer thin films on silicon substrate by magnetron sputtering, test the surface appearance, crystalline orientation, ferroelectricity and reflection spectrum of the multilayer thin films, and study the changing situation of property of multilayer thin films along with the increasing of period number. The results are as following:(1) The crystal particle dimension of the multilayer thin films is little by the Atom Force Microscope test, just several to more than ten nm, the surface is nearly flat.(2) All of the LNO thin films in [PZT/LNO]~n/Si are (110) preferred orientation polycrystalline structure; The PZT thin films in PZT/LNO/Si present (110), (101), (002) and (200) polycrystalline orientation; The PZT thin films in [PZT/LNO]~2/Si just present(110) and (200) polycrystalline orientation with weak diffraction peak; The PZT thin films in[PZT/LNO]~3/Si present (110) preferred orientation which induced by the LNO presenting (110) preferred orientation, because the crystal lattice of LNO and PZT match comparatively.(3) Periodic structures [PZT/LNO]~n/Si(n=1, 2, 3) show symmetrical Polarization-Voltage hysteresis loops. The range of applied voltage increases while the leakage current reduces with the increase of period number. (4) There is an increasing trend in the reflection spectrum of multilayer thin films with the increasing of wavelength. There is an oscillating in the reflection spectrum of the three period structure [PZT/LNO]~3/Si, this is influenced by the periodic structure to the light behavior.