Two YBa2Cu3O7-x, materials (YBCO-I sintered at 1000 degrees C, and YBCO-II sintered at 960 degrees C and following special cooling programs) belonging to the orthorhombic system were obtained. YBCO-I has a complete volume texture, while for YBCO-II it is only on sample surface. On heating in air (with 10 K min(-1) in the temperature range 20-1000 degrees C), two endothermic processes are recorded on DSC curves (of YBCO-II) and they are due to oxygen diffusion from O1 to O5 sites, and then to the release into the environment; second endothermic effect is attributed to the decomposition reaction. Different behaviour is encountered on heating in argon: an endothermic process in two steps; continuous mass decrease (oxygen loss) during argon cooling is recorded on the thermo-gravimetric curve. In argon atmosphere, the obtained material shall correspond to the chemical composition: YBa2Cu3O6.77, while in air atmosphere, the maximal composition than may be obtained is: YBa2Cu3O6.88. The barrier energies from Arrhenius plots of resistivity vs. temperature (91-93 K) show 2D (YBCO-I) and 3D (YBCO-II) behaviour for the thermally activated flow of melted vortex lattice, below the critical temperature.

We propose a multi-technique approach based on in-vacuum synthesis of metal oxides to optimize the memristive properties of devices that use a metal oxide thin film as insulating layer. Pulsed Microplasma Cluster Source (PMCS) is based on supersonic beams seeded by clusters of the metal oxide. Nanocrystalline TiO2 thin films can be grown at room temperature, controlling the oxide stoichiometry from titanium metal up to a significant oxygen excess. Pulsed Electron beam Deposition (PED) is suitable to grow crystalline thin films on large areas, a step towards producing device arrays with controlled morphology and stoichiometry. Atomic Layer Deposition (ALD) is a powerful technique to grow materials layer-by-layer, finely controlling the chemical and structural properties of the film up to thickness of 50-80 nm. We will present a few examples of metal-insulator-metal structures showing a pinched hysteresis loop in their current-voltage characteristic. The structure, stoichiometry and morphology of the metal oxide layer, either aluminum oxide or titanium dioxide, is investigated by means of scanning electron microscopy (SEM) and by Raman scattering.

We propose a multi-technique approach based on in-vacuum synthesis of metal oxides to optimize the memristive properties of devices that use a metal oxide thin film as insulating layer. Pulsed Microplasma Cluster Source (PMCS) is based on supersonic beams seeded by clusters of the metal oxide. Nanocrystalline TiO2 thin films can be grown at room temperature, controlling the oxide stoichiometry from titanium metal up to a significant oxygen excess. Pulsed Electron beam Deposition (PED) is suitable to grow crystalline thin films on large areas, a step towards producing device arrays with controlled morphology and stoichiometry. Atomic Layer Deposition (ALD) is a powerful technique to grow materials layer-by-layer, finely controlling the chemical and structural properties of the film up to thickness of 50-80 nm. We will present a few examples of metal-insulator-metal structures showing a pinched hysteresis loop in their current-voltage characteristic. The structure, stoichiometry and morphology of the metal oxide layer, either aluminum oxide or titanium dioxide, is investigated by means of scanning electron microscopy (SEM) and by Raman scattering.

In this paper we report on the fabrication of n-doped ZnO and semiconducting n-ZnO at room temperature by a new ablation deposition technology that makes use of electron/plasma ablation sources named Pulsed Plasma Deposition (PPD) developed by Organic Spintronics Srl. The oxygen vacancies n-doped ZnO PPD grown thin film is deposited on PET and shows a resistivity of 3 × 10^-4 ohm cm. The n-ZnO TCO is compact, smooth and highly transparent in the UV-VIS (better than 90 T%) as well as in the near IR spectral range and it is remarkably temperature stable. Typical ZnO deposition rate of the PPD is 500 nm/min. The RT deposited semiconductor ZnO shows a very large Hall electron mobility up to 1000 cm²/Vs approaching that of the single crystal. Preliminary results of Si/SiO<inf>2</inf> based bottom gate and contact FET test pattern structures with a 50 nm overlaying ZnO thin film shows an ON/OFF ratio of 50000 and a FET mobility of 1 cm²/Vs. Further implementation on appropriate FET design will be performed to explore the possibility to achieve a larger FET mobility. The PPD proves to be an enabling technology that makes it possible the advent of flexible OLED displays.

CdTe and CdS are emerging as the most promising materials for thin film photovoltaics in the quest of the achievement of grid parity. The major challenge for the advancement of grid parity is the achievement of high quality at the same time as low fabrication cost. The present paper reports the results of the new deposition technique, Pulsed Plasma Deposition (PPD), for the growth of the CdTe layers on CdS/ZnO/quartz and quartz substrates. The PPD method allows to deposit at low temperature. The optical band gap of deposited layers is 1.50 eV, in perfect accord with the value reported in the literature for the crystalline cubic phase of the CdTe. The films are highly crystalline with a predominant cubic phase, a random orientation of the grains of the film and have an extremely low surface roughness of 4.6±0.7 nm r.m.s.. The low roughness, compared to traditional thermal deposition methods (close space sublimation and vapour transport) permits the reduction of the active absorber and n-type semiconductor layers resulting in a dramatic reduction of material usage and the relative deposition issues like safety, deposition rate and ultimately cost

NOVELTY - Device (1), for generating plasma and for directing an flow of electrons towards a target (3), comprises a hollow element (5) which has a cavity (6) and is designed to act as a cathode; a main electrode (7); a substantially dielectric tubular element (21), which extends through a wall (22) of the hollow element (5) from the cavity (6) to an external chamber (24); and an external element (25) which is designed to act as an anode. USE - The device is used for generating plasma and for directing a flow of electrons towards a target. Te apparatus is used for applying on a substrate a specific material (all claimed). ADVANTAGE - The present invention provides a device for generating plasma, and an apparatus and a method for applying a layer of a material on a support. DETAILED DESCRIPTION - Device (1), for generating plasma and for directing an flow of electrons towards a target (3), comprises a hollow element (5) which has a cavity (6) and is designed to act as a cathode; a main electrode (7); a substantially dielectric tubular element (21), which extends through a wall (22) of the hollow element (5) from the cavity (6) to an external chamber (24); and an external element (25) which is designed to act as an anode, is externally placed with regard to the hollow element (5) and is exterior to and along the tubular element (21); the device (1) comprises an activation group (11) which is electrically connected to the hollow element (5) and can reduce the electric potential of the hollow element (5) of at least 8 kV in less than 20 ns; the main electrode (7) is at least partially placed inside the cavity (6) of the hollow element (5). INDEPENDENT CLAIMS are: (1) apparatus, for applying on a substrate (4) a specific material, comprises an external chamber (24), a target (3) made of a specific material and placed in the external chamber (24); the apparatus (1) comprises a device (2) above, the cavity (6) of the device and the external chamber (24) communicating and containing gas at a pressure lower than 10-2 mbar; the device (2) being able to direct an flow of electrons against the target (3) so that at least a part of the specific material is removed from the target (3) and settles on the support (4); and (2) a method of applying a specific material on a support (4) comprises an emission step, during which a device (1) above directs an flow of electrons against a target (3) with the specific material in order to remove at least a part of the specific material from the target (3) and to direct it towards the support (4).

The channel spark discharge was used as a high-current density (up to 30 kA/cm(2)) relatively low-energy (<20 keV) electron beam source in a pulsed plasma deposition (PPD) gun. The PPD gun was used for the deposition of thin films by pulsed ablation of different target materials, at a background gas pressure in the 10(-3)-10(-5) Torr range. The parameters of the electron beam generated in the modified PPD gun were studied using electrical, optical, and X-ray diagnostics. It was found that a higher background pressure stimulates a denser plasma formation between the gun output and the target, that restricts the energy delivery to the beam electrons. Namely, the efficient (up to similar to 74%) transfer of the initially stored energy to the electron beam is realized at the background gas pressure of 10(-4) Torr. Conversely, at a pressure of 10(-3) Torr, only <= 10% of the stored energy is acquired by the energetic electrons. It was shown that the modified PPD gun, owing to the extremely high energy density delivered by the electrons to the target, may be applied for the deposition of a wide variety of different insulators, semiconductors, and metals. A selection of materials such as diamond-like carbon (DLC), cadmium telluride (CdTe), cadmium sulphide (CdS), zinc oxide (ZnO), tungsten, and tungsten carbide (WC) have been deposited as thin films and the properties and deposition rates of the deposited thin films are discussed. (C) 2011 The Japan Society of Applied Physics

We present the results for a channel spark discharge which show a substantial difference between the pressure in the experimental chamber and the pressure in the hollow cathode (HC). For the pressure range (1-8) x 10(-2) Torr measured in the experimental chamber, the pressure in the hollow cathode is changed in the range (8-16) x 10(-2) Torr. An analysis of the pressure data obtained by pumping of the experimental chamber via the HC showed that there are three modes of the system pumping, namely molecular, transient and viscous. Finally, it was shown that applying a discharge voltage with amplitude up to 50 keV allows electron beams to be generated with an efficiency up to 10%, a maximum electron energy spectrum at about 25 keV and a current amplitude of several hundred amperes.

Parameters of an arc Ar plasma discharge used as a plasma window with a discharge current of 50 A and a voltage of 58 V are presented. It is shown that this arc discharge allows one to decrease the pressure at the low pressure end of the plasma window almost 380 times using relatively low pumping at the low pressure end of the plasma window. Calculations of the plasma parameters and their spatial distribution using a simple wall-stabilized arc model showed a satisfactory agreement with the experimentally obtained data. It is shown that a significant decrease in gas flow through the plasma window occurs due to the increase in plasma viscosity. An improvement of the plasma window ignition and some of its design aspects are described as well.

A novel approach to increase the efficiency of solid-state Gratzel solar cells is presented. Large surface, titania inverse opal films is prepared, and used in fabricating solid-state dye sensitised organic-inorganic hybrid Gratzel solar cells. The ordered interconnected cavities forming the microporous structure allow an easy and desired penetration of both the dye and the solid-state hole conductor material favouring the intimate contact of both these elements through the whole depth of the titania. These cells show much higher efficiency as compared to solid-state Gratzel cells prepared, in twin procedures, by conventional method using nanocrystalline TiO2 films.

Spintronics is a new branch of electronics based on purely quantum effects. Instead of carrier's charge transfer as in usual electronics, it evokes carrier's spin transfer. The search of new materials suitable for injecting and transferring carriers with a preferential spin orientation is of paramount importance for the development of spintronics. Here we report the results of the investigation of the spin polarization of the La0.7Sr0.3MnO3 manganite films and the spin polarized injection from the manganite into ?-conjugated organic semiconductors. The surface of the La0.7Sr0.3MnO3 films at room temperature is composed of homogeneous ferromagnetic (FM) phase in which paramagnetic (PM) defects are embedded. The ferromagnetic phase is highly spin polarized showing a room temperature half-metallic behavior. A strong magnetoresistance (up to 30%) was measured on nanostructured planar hybrid junctions LSMO/sexithiophene/LSMO indicating both the spin polarized injection and the spin polarized transport up to distances of about 100 nm at room temperature.

In this paper we propose a simple model for the formation of monodisperse polymer colloids, which provides a convenient set of synthetic parameters for given bead diameters. We provide experimental data in support of this model.

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Results of a colloidal crystal growth by vertical deposition of nanometric polystyrene beads on a glass substrate under oscillatory shear are reported in this paper. This technique of deposition enabled us to study an early stage of the growth of films as a function of the bead concentration in the water suspension. The surprising analogy between single layer growth and the bulk colloidal crystal behavior has been found. Indeed, the sequence of transitions from low density disordered (LDD) phase to intermediate density ordered phase and then to high density ordered phase with increasing bead concentration has been observed. © 2003 Elsevier Science B.V. All rights reserved.

The ferromagnetic phase in La0.7Sr0.3MnO3 manganite is completely spin polarized (100%) at room temperature. This is demonstrated on high quality epitaxial films by Spin-Polarized Scanning Tunneling Microscopy. The films consist of a highly homogeneous ferromagnetic (FM) phase in which minority paramagnetic (PM) defects are embedded (less than 1% for best films). PM defects exhibit featureless tunneling spectroscopic characteristics and an insulating-like conductance. FM phase exhibit metallic behavior and strongly nonlinear characteristics. Deconvolution of the spectroscopic curves for the FM phase reveals the totally spin-splitted egt2g manganite bands whose shape and width are in an excellent agreement with optical and photoemission spectroscopy data. These results promote the manganites as efficient spin polarized injectors at ambient conditions.

Results of a colloidal crystal growth by vertical deposition of nanometric polystyrene beads on a glass substrate under oscillatory shear are reported in this paper. This technique of deposition enabled us to study an early stage of the growth of films as a function of the bead concentration in the water suspension. The surprising analogy between single layer growth and the bulk colloidal crystal behavior has been found. Indeed, the sequence of transitions from low density disordered (LDD) phase to intermediate density ordered phase and then to high density ordered phase with increasing bead concentration has been observed.

A method for absorbing formaldehyde from gaseous mixtures that containing it, and a method for regenerating the absorption compound used

Intensity enhancement of the optical stop band of a periodic quasicrystalline structure is achieved by infiltrating this structure with a suitable dye, as demonstrated for monodisperse polystyrene beads doped with the organic dye Oil Red EGN. A detailed discussion of the optical properties of the system is given in terms of the Bragg and Snell laws, and constraints concerning the refractive index of the dye, LATEX bead diameter, and quasicrystal lattice are extracted. Following some simple geometrical constraints the opening of the photonic bandgap can thus be tuned.

A process for absorbing nitrogen oxides, comprising the step of placing gas mixtures containing nitrogen oxides in contact with absorbent compounds constituted by mixed copper oxides chosen among CaCuO2, Sr4Cu24O41, derivatives thereof obtained by isovalent and/or heterovalent substitutions, and mixtures thereof