Vortex lattice matching effects in superconducting Mo$_{3}$Si films with magnetic pinning centers.

Electron Beam Lithography and sputtering techniques have been used to fabricate arrays of Ni nanodots on Si (100) substrate. Nb films and amorphous Mo$_{3}$Si films were grown on top of the magnetic array by magnetron sputtering. The same arrays were used in both superconducting systems; therefore the same periodic pinning potential is induced in both systems. Magnetotransport and (I, V) curves were measured close to the films critical temperatures. Matching effects are observed between the periodic array of pinning potentials and the driving vortex lattice. The different vortex dynamics will be discussed in both systems. We want to thank Spanish Ministerio Educacion y Ciencia grants NAN2004-09087, FIS2005-07392.