Tunneling and anisotropic charge transport properties of superconducting (110)-oriented YBa2Cu3O7 thin films

We have measured the tunneling conductance of YBa2Cu3O7/Pb planar tunnel junctions fabricated on superconducting (110)-oriented YBa2Cu3O7 thin films exhibiting zero-resistance superconducting transition temperatures (T-c's) between 88 and 89.5 K. The conductance is the same as we and other groups have measured on (100)- and (103)-oriented YBa2Cu3O7/Pb junctions and quantitatively different from c-axis tunneling. The ab-plane transport is comparable to that measured in (001)-oriented YBa2Cu3O7 thin films, and the transport anisotropy varies between 65 and 80 from 300 K to T-c, respectively. This anisotropy is higher than that previously measured in both (110)-oriented and c-axis aligned (100)-oriented films, but it is comparable to that measured in single crystals. (C) 1996 American Institute of Physics.