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Abstract: CaCu3Ti4O12 (CCTO) thin film was prepared on LaNiO3 (LNO)-coated silicon substrate by a sol–gel process. The CCTO sample is perovskite structure without any detectable impurities. Compared with the films grown on platinum (Pt), the CCTO thin film on LNO exhibits the (400) preferential orientation. It may be due to the LNO acts as seed layer during the growth of the CCTO film. It is indicated that the dielectric loss of CCTO thin film on LNO is lower than that of the films on Pt. The dielectric response of CCTO thin film on LNO can be described with the Debye relaxation model subjoining the contribution of conductance and diffusion effect. [Copyright &y& Elsevier]

BiFeO3 thin films have been grown on Pt(111)/Ti/SiO2/Si substrates by chemical solution deposition. It is shown that the films are polycrystalline by the measurement of X-ray diffraction. The infrared optical properties of BiFeO3 thin films have been investigated using the infrared spectroscopic ellipsometry in the wavelength range of 2.5 to 12.6 μm. The infrared optical constants of the BiFeO3 thin films are obtained by fitting the measured ellipsometric spectra data using a three-medium model and a classical dielectric function model. The absorption coefficient of BiFeO3 thin films is greater than 100 cm-1 in total measured wavelength region and greater than 1000 cm-1 at the wavelength region above 7.5 μm. It is bigger than that of PbTiO3, Pb(Zr,Ti)O3 and (Pb,La)(Zr,Ti)O3 thin films. It indicates that the BiFeO3 thin films are excellent candidates for infrared detectors. [ABSTRACT FROM AUTHOR]

Abstract: BiFeO3 (BFO) thin films were grown by chemical solution deposition on SrTiO3 (100) substrate. LaNiO3 thin films were used as the bottom electrode. X-ray diffraction pattern indicated that the samples exhibited highly (100) oriented. Scanning electron microscopy showed that the BFO thin film possessed a dense microstructure and grains in BiFeO3 thin films were columnar. The remnant polarization of BFO thin films was 0.86μC/cm2 when 375kV/cm electric field was applied at 80K. The conductivities of the samples at room temperature and 80K were smaller than 10−12 Ω−1 cm−1. At 80K, the permittivity of the BFO thin films decreased from 76 to 62 linearly with the frequency increasing from 1kHz to 1MHz. The dielectric loss was about 0.05 when the frequency was in the range of 1000–100kHz, and was lower than 0.2 when the frequency was lower than 1MHz. The pyroelectric coefficient at room temperature was 1.47nC/(cm2 K). [Copyright &y& Elsevier]