We have proposed ReMnO3 (Re:rare earth) thin films as a new candidate for nonvolatile memory devices. In this letter, we report on fabrication of (0001) YMnO3 films on (111)MgO, (0001)ZnO:Al/(0001) sapphire, and (111)Pt/(111)MgO using rf magnetron sputtering. We succeeded in obtaining (0001) epitaxial YMnO3 films on (111) MgO and (0001)ZnO:Al/(0001) sapphire substrate, and polycrystalline films on (111)Pt/(111)MgO. The dielectric properties of the epitaxial and polycrystalline YMnO3 films are almost the same. The dielectric permittivities of both films are smaller than those reported for YMnO3 single crystal.

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A Molecular Dynamics simulation of a solution of one Li+ in 215 NH3 molecules has been performed at an average temperature of 235 K. A newly developed flexible model for NH3 is employed and the Li + -NH3 interactions are derived from ab initio calculations. The structure of the solution is described by radial distribution functions and the orientation of the molecules. A solvation number of six is found for Li+ and a strong preference of the solvation shell molecules exists for an orientation where the Li + -N vector and the dipole moment direction of NH3 are parallel. The self-diffusion coefficient, the hindered translational motions and librations are calcula ted separately for the ammonia molecules in the solvation shell and in the bulk. The effect of Li + on intramolecular geometry and vibrations is reported. The physics of metal solutions in liquid ammonia is an interesting topic in modern physical chemistry. For example, striking differences between solvation of metal atoms in water and liquid ammonia exist. Diss olving alkali metal atoms in water leads to oxidation to the monovalent cations, the formation of hydroxide ions, and H2 evolution. On the contrary, in liquid ammonia free electrons exist if the alkali metal con centration exceeds a few mole percent [1], The electri cal conductivity of a 20 mole percent lithium solution is higher than that of liquid mercury at room tempera ture [2], Structural information about bulk ammonia as well as metal ion and electron solvation is necessary in order to understand the properties of these solutions. The only X-ray scattering experiment on liquid am monia reported so far has been performed by Narten [3]. Only the nitrogen-nitrogen radial distribution function (RDF) can be extracted reliably from these data. The available neutron scattering data [4] are not analysed in terms of atom-atom RDFs. Neutron scat tering experiments with isotopic substitution, which yield information also about the nitrogen-hydrogen and hydrogen-hydrogen RDFs, have not been per formed. Considerable efforts have been made in attempts to overcome this lack of experimental information on liquid ammonia by means of computer simulations [5][6][7][8][9], which yield information about all three atomatom RDFs. Recently, the electron solvation in liquid ammonia has been treated by the quantum path inte gral Monte Carlo method on the basis of a pseudopotential ansatz for the electron ammonia interactions [10].In this work, the structure of the solvation shell of a lithium ion dissolved in NH3 will be discussed in detail and compared with some preliminary results from a neutron diffraction experiment [4] and a recent Molecular Dynamics (MD) simulation [11]. In addi tion, the dynamical properties of ammonia in the bulk and in the solvation shell of the ion have been calcu lated separately from the simulation and are com pared with experimental data. The flexibility of the ammonia model employed permits the investigation of the effect of Li+ on the intramolecular vibrations of NH3 and the comparison...

The observation of nanoscale deformation in real time is a significant step toward understanding the mechanisms of friction and lubrication. Our experimental setup of a micromachine combined with a transmission electron microscope allowed us to measure the deformation, force and cross-sectional area of a single Ag asperity during shear testing. The experimental results provided insight into one of the parameters that determines the frictional coefficient. Furthermore, we demonstrated that the energy loss associated with a shear fracture event is strongly correlated with the increase in total surface energy of the two surfaces formed here after the fracture of the nanocontact.

Basic studies of nanometer scale phenomena, such as tribology, fusion bonding and deformation, are important for a MEMS/NEMS device. To better understand these nanometer scale phenomena, the combination of MEMS and transmission electron microscopy (TEM) setup is an invaluable tool. This combination allows for the direct observation of a deformation process at the nano-scale when a MEMS for the investigation of a nano-interface (MINI) device with sharp opposing tips is placed under a TEM. This paper describes the design and fabrication of a MINI that can perform an in situ experiment under TEM observation. We designed the MINI to minimize the misalignment of the opposing tips in order to provide adequate observation possibilities of the nanocontacts. In addition, we developed processes for the fabrication of a MINI and characterized it inside the TEM. Furthermore, silicon-silicon, gold-gold and silicon-gold opposing tips were designed and fabricated for experiments of the nano-interface of homogeneous and heterogeneous material. The MEMS tips were used to show an approach-contact-retraction-fracture cycle of a gold nanocontact under real-time TEM observation.

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Phylogenetic analyses were carried out on six pleurocapsalean strains and 12 oscillatorialean strains by sequence determination of the 16S rDNA (16S rRNA gene). Although heterocyst-forming strains of the orders Nostocales and Stigonematales were shown to be monophyletic, unicellular strains of the orders Chroococcales and filamentous Oscillatoriales were shown to be polyphyletic, as reported earlier. Moreover, unicellular and baeocyte-forming strains of the order Pleurocapsales, which were thought to be monophyletic, were newly found to be polyphyletic. The results strongly indicate that even morphology was not necessarily reflected in the phylogenetic relationships at the order level. A need exists to reconstruct the taxonomy of cyanobacteria at the order level. ß

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