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YBa2Cu3O7??thin films grown on a Nb-doped SrTiO3substrate by a pulsed laser deposition method have been fully characterized by scanning transmission electron microscopy Z-contrast imaging and electron energy loss spectroscopy techniques. The Nb distribution was found to be uniform and unchanged across the interface, ensuring a high quality p-n junction heterointerface. We first observed the coexistence of 124 and 125 YBCO defect structure phases, appearing as planar defects in a YBCO thin film. Dispersive Y2O3nanoparticles have also been observed in the thin film. The interaction of these defect structures and Y2O3nanoparticles is thought to be beneficial for pinning flux through the entire film thickness. [ABSTRACT FROM AUTHOR]

An all-perovskite ferroelectric field-effect transistor with a ferroelectric Pb(Zr[sub 0.2]Ti[sub 0.8])O[sub 3] (PZT) gate and a colossal magnetoresistive La[sub 0.8]Ca[sub 0.2]MnO[sub 3] (LCMO) channel has been successfully fabricated by pulsed-laser deposition on Si. A clear and square channel resistivity hysteresis loop, commensurate with the ferroelectric hysteresis loop of PZT, is observed. A maximum modulation of 20% after an electric field poling of 1.5×10[sup 5] V/cm, and 50% under a magnetic field of 1 T, are achieved near the metal-insulator transition temperature of the LCMO channel. A data retention time of at least one day is measured. The effects of electric and magnetic fields on the LCMO channel resistance are discussed within the framework of phase separation scenario. © 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR]

La0.7Sr0.3MnO3(LSMO) is a mixed-valent room temperature ferromagnet with properties that are attractive for their applicability in biomedicine. We report, for the first time, immobilization of commonly used biocompatible molecules on LSMO nanoparticles, namely bovine serum albumin and dextran. The former was conjugated to LSMO using 1-ethyl-3-(3-dimethyl aminopropyl)-carbodiimide (CDI) as a coupling agent while the latter was used without any coupler. These bioconjugated nanoparticles exhibit several properties that suggest their applicability in the field of biomedicine, namely (a) no changes in the Curie temperature at ?360 K after conjugation with biomolecules, (b) rapid attainment of the desired temperature (48?°C) at low concentration (e.g. fluidized dextran-coated system at 80 µg ml?1) upon exposure to 20 MHz radio-frequency, (c) extremely low cytotoxicity in skin carcinoma, human fibrosarcoma and neuroblastoma cell lines and (d) high stability of the LSMO system with negligible leaching of ionic manganese into the delivery medium, indicating their safety in possible human applications. [ABSTRACT FROM AUTHOR]