Properties of HTS YBCO thin films deposited on tilted NdGaO3 substrates

Thin YBa2Cu3O7 films were fabricated by 2-opposed DC magnetron sputtering onto NdGaO3 substrates, tilted from standard (1 1 0) orientation by 0-26°, and their surface morphology and electrical characteristics were investigated. Normal state resistivity (at 295 K) and microwave surface resistance (at 77 K and ∼8 GHz) of the films demonstrated anisotropy, introduced by the tilted substrate, and some improvement of the superconducting parameters of the films was observed at small tilt angles (θ ∼ 1.5-3°). The increase of the microwave surface resistance at high tilt angles for the current tracks, perpendicular to the steps of the substrate, was described in the framework of a simple model, which takes into account the complex conductivity of the film and the weak links between the film terraces.