Anisotropic transport properties in tilted c-axis MgB2 thin films

We report on superconducting magnesium diboride MgB2 thin films grown on both YSZ and MgO substrates, with two different orientations, namely [110] and [211]. MgB2 off-axis growth mode (namely, with the c-axis tilted with respect to the film surface's normal) is achievable on these substrates. Depending on the type and orientation of the substrate, tilting angle can be varied. As a consequence of tilted growth, anisotropic transport properties are observed. In very thin films, resistance measurements provide an estimate of the resistivity anisotropic ratio rho(c)/rho(ab), where rho(c) is the resistivity along the c axis and rho(ab) is the in-plane resistivity. All these findings clearly demonstrate that tilted MgB2 films offer new exciting possibilities to both investigate intrinsic fundamental properties of MgB2 and to explore possible applications in planar superconducting devices.