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Investigating the structural and morphological properties of Ni-11at %V and Ni-5at% W substrates, as well as their influence on the superconducting transport properties of the YBCO superconducting architectures is presented. It is concluded that the Ni-W substrate has a larger percolation are, mainly due t the absence of twinned grains, and a higher oxidation resistance.

The cables and windings integrated in electric power devices require long high critical current density Bi-2223/Ag tapes. INFN, Europa Metalli and CISE SpA are jointly developing 100-meter-long silver-sheathed multifilamentary Bi-2223/Ag tapes through the powder-in-tube process. They also employ the react-and-wind method for the thermomechanical processing and winding of the tapes into double pancakes.

We report on the growth of MgB[SUB2] thin films by means of Pulsed Laser Deposition (PLD) and Electron Beam (EB) deposition techniques. In order to develop an in-situ deposition procedure both techniques have been exploited following two approaches: the "as grown" procedure, where the superconducting phase is formed during the film growth, and no further process is performed, and the "annealing" procedure, where precursor layers are deposited and annealed in argon atmosphere. In the case of EB evaporated films, the "as grown" procedure revealed to be inadequate, because of the low reactivity of the thermally evaporated species and the high magnesium volatility. On the contrary, using PLD, the higher reactivity of the plasma species promotes the formation of the superconducting phase at deposition temperature as low as 350°C. In the "annealing" procedure, different kinds of precursor layers have been studied, in order to reduce and prevent the fast Mg evaporation at high temperature. Different annealing processes were investigated in order to promote the interdiffusion and reaction between Mg and B. The films were characterised by means of resistivity measurements and X-ray analyses. The surface morphology was observed by SEM microscopy. [ABSTRACT FROM AUTHOR]

A study on CeO[SUB2] film growth on randomly oriented metallic substrate using Inclined Substrate Deposition (ISD) technique was performed in order to develop a biaxially aligned buffer layer for YBa[SUB2]Cu[SUB3]O[SUB7-δ] (YBCO) coated conductors. The influence of deposition parameters, as the substrate inclination angle α with respect to the CeO[SUB2] vapor direction, deposition temperature and film thickness, on structural and morphological properties of the film was investigated. At substrate temperature between 200°C and 700°C a biaxial texture was observed for α ranging from 15° to 75°. The minimum value of the φ-scan full width at half maximum (FWHM) on (002) poles of about 13.5° was obtained for film 2 μm thick deposited at 200°C and α = 55°. Morphological analyses on cross-sectioned samples revealed a columnar structure, typical for this deposition technique, with spaced grains and a tile like surface. [ABSTRACT FROM AUTHOR]

A Modified-Melt-Powder-Melt-Growth (MMPMG) technique has been developed for the preparation of melt-textured Y-Ba−Cu−O pellets. To test their performances, the samples were characterized with respect to their microstructure, pinning strength and interaction force with permanent magnets. A superconducting magnetic bearing was built and integrated in a levitating flywheel system for energy storage. [ABSTRACT FROM AUTHOR]

The thermal conductivity of Ge2Sb2Te5 (GST) layers, as well as the thermal boundary resistance at the interface between the GST and amorphous SiO2, was measured using a photothermal radiometry experiment. The two phase changes in the Ge2Sb2Te5 were retrieved, starting from the amorphous and sweeping to the face centered cubic (fcc) crystalline state at 130 °C and then to the hexagonal crystalline phase (hcp) at 310 °C. The thermal conductivity resulted to be constant in the amorphous phase, whereas it evolved between the two crystalline states. The thermal boundary resistance at the GST-SiO2 interface was estimated to be higher for the hcp phase than for the amorphous and fcc ones. [ABSTRACT FROM AUTHOR]

Biaxially aligned YBa2Cu3O7−δ (YBCO) thick films were deposited by pulsed laser ablation technique on cube textured non-magnetic Ni89V11 (Ni–V) substrate, using CeO2/YSZ/CeO2/NiO buffer layer architecture. The first NiO seed layer was formed by epitaxial oxidation of the Ni–V substrate. Structural analyses show typical full width at half maximum values of φ- and ω-scans less than 10° and 8°, respectively. The highest value obtained for the critical current density at 77 K and zero magnetic field was 6×105 A cm−2, which is close to that obtained for YBCO films grown on CeO2/NiO buffer layer architecture. [Copyright &y& Elsevier]