Epitaxial thin films of LaNiO 3−x were deposited by using a reactive d.c. magnetron sputtering technique. High-energy X-ray photoelectron spectroscopy was used to analyze the composition and valence states of La and Ni in the films after long time aging in atmosphere. The obtained results show the existence lanthanum and nickel in oxide and hydroxide chemical states. The oxygen exists in four chemical states: lattice oxides, hydroxyl groups and in adsorbed water. Comparison of the spectra recorded at normal emission and grazing emission angle revealed that the hydroxyl group's concentration is mostly present at the surface of the film.

Here we present for the first time a study of the photoresistive properties and dynamics of ordered, high-density arrays of germanium nanowire photoresistors. Germanium is a wellknown semiconducting material with an indirect bandgap, E g , of approximately 0.66 eV (temperature T = 300 K) [1] and has been widely used for the fabrication of photodetectors, [2][3][4][5] radiation detectors, [6][7][8] charged particle and photon tracking devices, [9] far-infrared photoresistors, [10] and numerous other devices. [11] During the last few years there has also been increasing interest in the use of nanostructures (quantum dots and wires) of both germanium and silicon as materials for potential applications in sensors, nanophotonics, and nanoelectronics. [12][13][14] However, in order to successfully integrate onedimensional semiconductors into useful devices, ordered architectures of aligned nanowires are required. Using templates such as anodized aluminium oxide (AAO) [15,16] or mesoporous materials [17,18] as hosts for nanowires offers a viable method for forming high-density arrays of ordered, crystalline nanowires. Significantly, AAO membranes with ordered and highly oriented pore structures have recently been synthesized on silicon substrates, [19,20] which is very promising for the integration of such materials into current complementary metal oxide semiconductor technologies. At University College Cork we have developed supercritical-fluid-inclusion phase methods for forming semiconductor [21][22][23] and metal/ semiconductor core/shell [24] nanowires and nanotubes within the pores of mesoporous matrices and AAO membranes.Supercritical-fluid-inclusion methods are ideal solvents for forming high-density arrays of nanowires within AAO templates as they do not suffer from the inherent problem of pore blocking associated with other methods, such as electrodeposition and incipient wetness techniques. The electrical conductivity and photoluminescence properties of semiconductor nanowire arrays have been investigated by several research groups. [25][26][27][28] However, photoconductivity measurements on ordered semiconducting nanowire arrayshave not yet been performed. An investigation into the photoconductivity of ordered arrays of nanowires is important in order to fully understand their potential in future photodetection devices, for example, as photoresistors or photodiodes. In this paper, we report the photoconductive properties of germanium nanowire photoresistors with mean diameters of 50 and 100 nm, incorporated within the pores of AAO membranes. A comparative study of the photoresistive properties of germanium nanowire photoresistor arrays with different optically transparent electrodes, namely ultrathin gold films and tin-doped indium tin oxide (ITO) layers, is described in this paper. ITO is a well known n-type semiconductor widely used in the fabrication of transparent electrodes in various optoelectronic devices. [29] To our knowledge, this study is the first analysis of photoconductivity in ordered semicond...

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YBCO thin (about ) films were deposited at on (001) by single-source injection CVD. Precisely controlled microamounts of organometallic -diketonates dissolved in an organic solvent were injected sequentially into the evaporator by means of a computer-driven injector and the resultant vapour was transported into the deposition zone. The influence of the vapour phase composition on films' properties was investigated. A mixture of and -oriented YBCO crystallites exists in all deposited films and its ratio depends on the vapour phase composition. For both a and c perpendicular crystallites only in-plane orientation with respect to substrate axes was found. Bidirectional twinning was established in the crystallites of both types. of the films (about 90 K) was almost independent of the vapour phase composition in the studied range. However, the critical current density depended clearly on the vapour phase composition in relation to the ratio variation. of the films varied in the range .

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