Vortex phase diagram in BSCCO with damage tracks created by 30 MeV fullerene irradiation

摘要

Using 30 MeV C60 fullerene irradiation, we have produced latent tracks ofdiameter 20 nm and length 200 nm, near the surface of single crystalline BSCCO.A preliminary transmission electron microscopy study shows evidence for a veryhigh density of deposited energy, and the ejection of material from the trackcore in very thin specimens. The latent tracks reveal themselves to beexceptionally strong pinning centers for vortices in the superconducting mixedstate. Both the critical current density and magnetic irreversibility line aresignificantly enhanced. The irradiated crystals present salient features of the(B,T) phase diagram of vortex matter both of pristine crystals, such as thefirst order vortex phase transition, and the exponential Bose-glass linecharacteristic of heavy ion-irradiated crystals. We show that the latter ismanifestly independent of the pinning potential.