Commensurbility effects in magnetic properties of superconductimg Nb films with periodic submicrometer nanodots

C. CHILIOTTE, D. PEREZ DAROCA, G. PASQUINI, V. BEKERIS, C.-P LI, M. CASANOVA, J. VILLEGAS, I. SCHULLER

PHYSICA B - CONDENSED MATTER

Elsevier

Año: 2009

0921-4526

Pinning properties in $100$ $nm$ thick continuous and porous superconducting Nb films are examined by $ac$ suscepetibility and $% dc$ magnetization measaurements. The Nb film was deposited on a smooth  Si substrate, while the porous film, NbP,  was deposited on an anodizedAl oxide substrate.  Pores or extquotedblleft antidots extquotedblright 40 nm in diameter,  100 nm apart,  form a triangular array. The porous film presents commensurate or matching fieldeffects for applied magnetic fields where the magnetic flux threading each unit cell is an integer number of the flux quantum, where $ac$ shielding capability and $dc$ diamagnetic magnetization show an abrupt increase. The response to $ac$ fields as a function of temperature and $dc$ field provided a way to determine that NbP sample has higher pinning than thecontinuous one, and that $T_{C}$ suppression due to fluxoid quantization is not relevant for the investigated temperature range.