Suppression of dissipation in Nb thin films with triangular antidot arrays by random removal of pinning sites

The depinning current Ic versus applied magnetic field B close to the transition temperature Tc of Nb thin films with randomly diluted triangular arrays of antidots is investigated. Our experiments confirm essential features in Ic(B) as predicted by Reichhardt and Olson Reichhardt [Phys. Rev. B 76, 094512 (2007)]. We show that, by introducing disorder into periodic pinning arrays, Ic can be enhanced. In particular, for arrays with fixed density nₚ of antidots, an increase in dilution Pd induces an increase in Ic and decrease of the flux-flow voltage for B>Bₚ=nₚΦ₀.