Anisotropy and Lorentz-force dependence of the critical currents in ${\mathrm{YBa}}_2$${\mathrm{Cu}}_3$${\mathrm{O}}_{7\mathrm{-}\mathrm{\delta }}$ thick films deposited on nickel-alloy substrates

We investigate the angular dependence of the critical currents in ${\mathrm{YBa}}_2$ ${\mathrm{Cu}}_3$ ${\mathrm{O}}_{7\mathrm{-}\mathrm{\delta }}$ thick films deposited on metallic nickel-alloy substrates, with the aid of an yttria-stabilized zirconia buffer layer. Overall, the critical current shows a clear Lorentz-force dependence and two distinctive peaks, one for fields parallel to the ab plane, due to bulk intrinsic pinning by the layered structure of the superconductor, and the other for fields parallel to the c axis, which we attribute to twin-boundary c-axis correlated pinning, as suggested by its Lorentz-force dependence.