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Abstract: Multilayers of2wt-% Pr-and4wt-% BaZrO3-doped YBa2Cu3O6+x (YBCO) were deposited by pulsed laser ablation on SrTiO3 and MgO single crystals. The structural and superconducting properties of the multilayers are presented. Multilayering was found to improve the critical temperature and structural quality of the samples on SrTiO3, but it did not change the critical current density. On MgO, the critical temperature improved slightly,but the critical current density decreased. [Copyright &y& Elsevier]

Superconducting YBa2Cu3O6+x (YBCO) films are grown by pulsed laser deposition (PLD) in the orientation where its c-axis is lying in the plane of the film using (110) oriented SrTiO3 (STO) substrates with PrBCO template layer. By optimization of deposition temperature and rate the easily formed (103) orientation was avoided to get smooth and completely (110) oriented YBCO films. To improve the superconducting properties, we have also optimized the BaZrO3 (BZO)-doping in the (110) YBCO films. This gives the possibility to apply the current along the YBCO CuO2 planes where the critical current is much higher in thin film multilayers or to investigate the anisotropy and the effect of BZO pinning structure in different film orientations. [ABSTRACT FROM AUTHOR]

We report the effect of 4 wt% BZO-doping in GdBCO thin films on (100) STO substrates with novel nanograined target materials deposited by pulsed laser deposition (PLD) method. X-ray diffraction, atomic force microscopy and magnetization measurements, which were made in particularly wide temperature and magnetic field range, were used to determine the structural and superconducting properties. The results were compared with ones of YBCO. The deposition temperature, Ts, is not very critical for GdBCO and it is found to be much lower in undoped and BZO-doped GdBCO than in YBCO. The BZO-doping of GdBCO enhanced the field dependence of critical current density, jc, at low temperatures. Furthermore, BZO-doping enhances the accommodation field, B*, below 60 K being clearly higher at 10 K in doped GdBCO than in YBCO. The pinning mechanism in GdBCO was concluded to be similar to that of YBCO. Our results clearly show that undoped and BZO-doped nanophase GdBCO is a very promising target material for applications as well as for coated conductors. [ABSTRACT FROM AUTHOR]

Studies thermally induced motion and clustering of single particles obtained by pulsed laser deposition (PLD) from uniform size Y-Ba-Cu-O superconducting thin films. Average height and radius of particles after annealing at different temperatures; Dependence of the average height and radius of the particles on temperature.

We report photo-induced colossal magnetoresistive insulator-metal transition (IMT) in Pr 0.6 Ca 0.4 MnO 3 thin films under much reduced applied magnetic field. The colossal effect was studied as a function of film thickness and thus with variable structural properties. Thorough structural, magnetic and magnetotransport characterization under light shows that the highest effect on the transition field can be obtained in the thinnest film (38 nm). However, due to the substrate induced strain of this film the required magnetic field for IMT is quite high. The best crystalline properties of the 110 nm film lead to the lowest IMT field under light and 10 9 % change in resistance at 10 K. With increasing thickness, the film properties start to move more toward the bulk material and, hence, IMT is no more observed under the applied field of 9 T. Our results indicate that for obtaining large photo-induced CMR, the best epitaxial quality of thin films is essential. [ABSTRACT FROM AUTHOR]

Abstract: We have introduced artificial pinning centres in thick (>1μm) YBCO films grown by Pulsed Laser Deposition using substrate decoration, quasi-multilayers, and target doping approaches. We have found that the frequency dependence of critical current density is consistent with a logarithmic dependence of pinning potential on current density. For most of materials used as nano-dots, artificially-induced pinning centres have a larger potential than natural ones. From angle-dependent in-field transport measurements and from Transmission Electron Microscopy we have found evidence of c-axis correlated pinning centres. [ABSTRACT FROM AUTHOR]