SURFACE NUCLEATION AT ABRADED SUPERCONDUCTOR SURFACES

Recent experiments described in the literature show that surface abrasion results in the persistence of superconductivity at enhanced magnetic fields. The suggestion has been made that the abrasion alters the boundary conditions at the superconductor surface, thus raising the surface nucleation field. Our results on In-0.7% Bi alloy foils show that this behavior is not related to conditions at the specimen boundary, but rather to the presence of a layer of severely deformed material. © 1969 The American Physical Society.