| Bismuth layer-structured ferroelectrics (BLSFs) have been investigated for the applications in ferroelectric random access memories, high temperature piezoelectric devices, and high-density capacitors due to its excellent endurance properties against polarization switching, high Curie temperature, and low loss tangent. These compounds belong to the Aurivillius family with a general chemical formula of (B2O2)2+(Am-1BmO3m+1)2-, where A is mono-, di- or trivalent elements with dodecahedral coordination, B is a transition cation suited to octahedral, and m is integer which presents the number of perovskite layers.SBTi has larger remnant polarization and fatigue-free behavior, but the low Curi Temperature (Tc=520℃) handicaps its practical use. Recently, higher Curie temperature materials are needed for higher temperature application. While CBTi has high Curie temperature (Tc=790℃), with the same structure of SBTi. So we did a series of experiments on replacing Sr2+ with Ca2+ of SBTi film and found that Ca0.4Sr0.6Bi4Ti4O15 (Ca0.4Sr0.6BTi) thin film exhibits good ferroelectric properties。LaNiO3(LNO), as a desirable candidate for electrode materials, has a pseudo-cubic perovskite crystal structure with good chemical and thermal stabilization.The lattice constant is 0.384 nm closed to some ferroelectric films, and has good crystal matche with ferroelectric thin films。Therefore, there are wider applications of LNO films on bottom electrodes of ferroelectric films. In this paper, preparation and properties of LNO films and Ca0.4Sr0.6BTi/LNO films were investigated in this dissertation.Firstly, LNO thin films were prepared on Si(100) substrates by sol-gel method. The effect of precursor concentration, pre-annealed temperature, annealed temperature, annealed time and thickness on resistivity and structure of LNO films was investigated. It is found that the low resistivity and high (110)-oriented LNO film made by decomposed at 350℃and then annealed at 750℃with 600s when the precurs or concentration is 0.2 mol/L. Besides, the epitaxial growth of LNO film on Si(100) was investigated. It is found that the epitaxial relationship is that:{LNO[110]//Si[100]}.Then, Ca0.4Sr0.6BTi thin films with LNO buffer layer were prepared using the sol-gel method. The X-ray diffraction patterns and SEM photographs exhibited that the (200)-oriented Ca0.4Sr0.6BTi thin film are homogeneous, crack-free and compact, with a-axis-orientation global crystals. Besides, the epitaxial growth of Ca0.4Sr0.6BTi film on LNO was investigated. It is found that the epitaxial relationship is that:(100)[Ca0.4Sr0.6BTi]//(110)LNO. The effects of different LaNiO3 buffer layer thicknesses on the structure and properties of Cao.4Sro.6BTi thin film were investigated. When the thickness of LNO layer is 250nm, the Ca0.4Sr0.6BTi thin film behaved a-axis orientation,I(200)/I(119) about1.2. The relative dielectric constant (εr), dielectric loss (tanδ), remnant polarization (Pr), and coercive field (Ec) were 230,0.068,17.5μC/cm2 and 84.6 kV/cm, respectively.Finally, the polycrystalline (200)-oriented Ca0.4Sr0.6BTi /LNO thin films were successfully prepared by sol-gel method at various conditions. The phase structure and morphology of films were characterized by X-ray diffraction (XRD) and a scanning electron microscope (SEM). The effects of different annealed temperature, pre-annealed temperature and spinning speed on the crystallization behavior of Ca0.4Sr0.6BTi/LNO films have been investigated. It is found that the Ca0.4Sr0.6BTi/LNO film with a-axis orientation(I(200)/I(119)=1.5) made by the spin coating at 4000r/m, decomposed at 400℃and then annealed at 725℃. The relative dielectric constant (εr), dielectric loss (tanδ), remnant polarization (Pr), and coercive field (Ec) were 249,19.4μC/cm2 and 50kV/cm, respectively.
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