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The anisotropy of the critical current density Jc was determined from angular critical current measurements for YBa2Cu3O6+x (YBCO) thin films laser deposited from a nanograined and a BaZrO3-doped nanograined target. In quantitative analysis using Blatter scaling the effective Jc anisotropy was found to be much smaller than for standard YBCO films. [ABSTRACT FROM AUTHOR]

Approximately 160-nm-thick (Hg0.9Re0.1)Ba2CaCu2Oy [(Hg,Re)-1212] epitaxial thin films were fabricated on 2°–18.4°-tilt SrTiO3 vicinal substrates with thin buffer layers. The vicinal films had superior crystallinity and superconducting properties comparable to those for conventional films with no tilt. X-ray diffraction measurements revealed that the tilt angles of the c axes of the (Hg,Re)-1212 are slightly larger by 0.5°–1.5° than the substrate tilt angles, which is attributed to deformation of crystal structure due to lattice mismatch in the c-axis direction. The resistivity and critical current density along the c-axis direction (ρc and Jc-c) were estimated to be ρc=500 mΩ cm at room temperature and Jc-c=(1.0–1.4)×105 A/cm2 at 10 K from transport measurements for different in-plane directions of the vicinal films. The ρc clearly exhibited semiconductor-like temperature dependence below 180 K. The temperature dependence of Jc-c almost agreed with the theoretical relationship for superconductor-insulator-superconductor junctions. The current–voltage characteristics in the directions across their a–b planes exhibited a multiple branch structure of intrinsic Josephson junctions with voltage jumps at intervals of approximately 20 mV at 4–40 K. [ABSTRACT FROM AUTHOR]

C-axis-oriented NdBa2Cu3O7-δ thin films (thickness ∼2000 Å) on LaAlO3 substrates have been prepared and irradiated with Ag+14 (200 MeV) ions at different inclinations (θd=0°, 15°, 30°, and 45°) to the c axis. Magnetization-field hysteresis loops have been obtained on pristine and irradiated thin films at two different temperatures in applied magnetic fields up to 5 T. Estimates of the critical current density Jc(H,θ) and the volume pinning force Fp(H,θ) from the magnetization data reveal a strong dependence on track inclination. An increase and a subsequent saturation in Fp(H,θ), instead of the usual Gaussian peak around the equivalent matching field, B[lowercase_phi_synonym], is observed. It is suggested that this dependence of Jc (or Fp) on θd is a consequence of the effective modification of vortex pinning by tilted columnar defects. [ABSTRACT FROM AUTHOR]

An as-grown MgB2 crystalline thin film was fabricated at a low temperature of 270°C on an in-plane-lattice near-matched TiZr buffer layer grown on a sapphire Al2O3 (0001) surface. The critical temperature and the superconductivity critical current density of MgB2/TiZr/Al2O3 were found to be high compared with those of MgB2/Al2O3. The film was characterized by using synchrotron x-ray diffraction. The epitaxial relationship in the plane was MgB2[0110]//TiZr[0110]// sapphire [1120]. In-plane-lattice spacings, d//MgB2, d//TiZr, and d//sapphire obtained were 0.268, 0.258, and 0.239 nm for the MgB2(0110), TiZr(0110), and sapphire (1120) planes, respectively. [ABSTRACT FROM AUTHOR]