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Amorphous bismuth-doped Al 2 O 3 thin films have been fabricated by atomic layer deposition method. The dielectric constant of the samples increases with the concentration of bismuth. Detailed electric processes are discussed based on the impedance spectroscopy and equivalent circuit model. It is found that the universal dielectric response (UDR) is ubiquitous in amorphous Al 2 O 3 . The dimensionality of the conduction space associated with the UDR process is not affected by the bismuth doping, but the alternating current conductivity associated with the UDR process increases with the bismuth concentration. The enhancement of dielectric properties is attributed to the 6 s lone pair electrons of bismuth. The result of capacitance vs. voltage measurement demonstrates that the bismuth-doped Al 2 O 3 film is suitable for the insulation layer in metal-oxide-semiconductor structure. [ABSTRACT FROM AUTHOR]

Abstract: Al-substituted α-type nickel hydroxides with different interlayer anions ( or ) have been synthesized by chemical coprecipitation method. The microstructure and morphology of the prepared samples were characterized by X-ray diffraction (XRD), infrared spectroscopy (IR), and scanning electron microscope (SEM). The effect of interlayer anions on the electrochemical performance of the prepared nickel hydroxides were investigated by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and charge/discharge tests. The results demonstrated that the Al-substituted α-type nickel hydroxide with interlayer has better electrochemical performance, such as better reaction reversibility, higher proton diffuse coefficient, lower electrochemical impedance, higher specific capacity, and better cyclic stability, than that of the Al-substituted α-type nickel hydroxide with interlayer . [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]