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Abstract: BiFeO3/LaNiO3 (BFO/LNO) heterostructure films are fabricated directly on Si (100) substrate. The LaNiO3 layer, which is prepared by chemical solution deposition, is used both as the seed layer to improve the quality of BiFeO3 layer, and as the bottom electrode for the electrical measurement. The BiFeO3 layer, which is fabricated by pulsed laser deposition, presents compact microstructure with grain size about 100nm. Saturated hysteresis loops of polarization vs. applied voltage have been measured at the frequency of 1kHz. The value of remnant polarization is about 40μC/cm2. The frequency dependence of capacitance and loss tangent of the heterostructure is also studied. All the results of the electrical measurements indicate that the effect of leakage current has been suppressed in the BFO/LNO heterostructure. The results are significative for the application of BiFeO3 films in microelectronic devices. [Copyright &y& Elsevier]

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]

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]