Growth and characterization of (110) oriented YBa_2Cu_3O_x superconducting thin films

摘要

High T_c superconducting thin films with high in-plane electrical anisotropy are currently of interest for practical structures such as microbridges and vortex flow devices. We present laser ablation growth conditions and electrical characterization (R(T), J_c, T_c etc) for (110) oriented YBCO thin films grown on a PBCO template layer on (110) oriented SrTiO_3 substrates. Films are grown to a maximum thickness of 200nm and are crack free. The bestfilms have an aft-plane resistivity of 150 μΩcm with T_c midpoint of 89K and T_c width of 3K. The anisotropy in the normal state in-plane resistivity at 100K may be varied up to the idear value of 1:100 by varying the processing conditions. We present I-V measurements taken over a range of temperatures and magnetic fields, and in particular note that the anisotropy in J_c in the low temperature limit is far less than the normal state anisotropy.