Structural and anisotropic transport properties of (Hg,Re)Ba2CaCu2Oy vicinal films

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=500mΩcm at room temperature and Jc-c=(1.0–1.4)×105A∕cm2 at 10K from transport measurements for different in-plane directions of the vicinal films. The ρc clearly exhibited semiconductor-like temperature dependence below 180K. The temperature dependence of Jc-c almost agreed with the theoretical relationship for superconductor-insulator-supe...