Thin films of multiferroic (Bi0.6Tb0.3La0.1)FeO3 were grown on Pt∕Ti∕SiO2∕Si substrate under various oxygen pressures by pulsed laser deposition technique. X-ray diffraction patterns show that the crystallinity of the thin film is improved with decreasing depositing oxygen pressure and the thin film grown at a lower oxygen pressure of 0.01torr exhibits a single perovskite phase with preferred (001) orientation. Leakage current of the as-deposited thin films decreases with decreasing grown oxygen pressure. Significantly, the leakage current of the thin films can be reduced largely by an annealing process at 800°C with flowing oxygen. The annealed thin films show a relatively high resistivity and stable polarization loops with double remnant polarization of about 3μC∕cm2. The conduction properties of the thin films have been well analyzed, and it is indicated that the dominant conduction mechanism is the space-charge-limited conduction for the thin film grown at higher oxygen pressure and the Poole-Frenkel conduction for the thin films grown at lower oxygen pressure.

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We report a novel sensitive terahertz spectroscopy in which both the electromagnetic generator and the detector are fabricated on the same chip. The radiation emitted from a tunnel-injected nonequilibrium high temperature (high-Tc) YBa2Cu3O7−y superconductor is detected by a high-Tc bicrystal Josephson junction. The observed data are converted to the spectral data by means of inverse Hilbert transformation. The resultant emitted spectra exhibit a broad peak around 1 THz, extending up to 2.5 THz. The relation to the Josephson plasma emission is discussed.

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