Effect of substrate-twin-induced microstructure on transport properties of epitaxial Tl2Ba2CaCu2O(x) films in a magnetic field

摘要

The role of substrate-induced microstructure on transport properties in c-axis oriented epitaxial Tl(sub 2)Ba(sub 2)CaCu(sub 2)O(sub x) films grown on LaAlO(sub 3) and SrTiO(sub 3) has been studied. For a magnetic field parallel to the Cu-0 planes, resistivity and the critical current density, J(sub c), have been measured as a function of angle (theta) between the applied field and the direction of transport current. Resistivity dips and enhancement of the critical current density, J(sub c), were observed for magnetic fields applied parallel to the substrate twins in LaAlO(sub 3) in high fields ((ge) 2 T). Meanwhile for films on SrTiO(sub 3), resistivity and J(sub c) were Lorentz-force independent.