Preparation of regular arrays of antidots in YBa↓(2)Cu↓(3)O↓(7) thin films and observation of vortex lattice matching effects

摘要

Optimized sputtered YBa↓(2)Cu↓(3)O↓(7) (YBCO) thin films on CeO↓(2)-buffered sapphire substrates are patterned into square lattices of submicrometer holes (antidots) with diameters of 250-450 nm and lattice parameters of d= 500-1000 nm without deterioration of superconducting properties. In the mixed state, matching effects between the Abrikosov vortex lattice and the artificial antidot lattice are observed. These effects are in the form of peaks or cusps in the critical current density recorded as a function of magnetic induction at integers n and specific rationals k/l of the matching field B↓(m)=(Φ↓(0)/d↑(2)) The experimental results are discussed in the context of existing theories. The existence of multiquanta vortices confined by the holes in YBCO films are considered. # 1997 American Institute of Physics. S0003-6951 (97)00431-2