Role of Boundary Conditions in Improving the Working Characteristics of
Superconductor - Based Nanostructures
Serghej L. Prischepa1,
V. N. Kushnir1, C. Attanasio2
1Belarus State University of Informatics and
RadioElectronics, P.Browka str., 6 Minsk 220013 Belarus.
2Physics Department "E.R.Caianiello", University of Salerno,
via S.Allende, 84081 Baronissi (SA), Italy.
We examined both theoretically and experimentally the effect of boundary
conditions on the critical parallel magnetic field Hc2par and the critical
current density Jc in superconductor based nanostructures.In particular, for
superconductor - normal metal superlattices we observed the influence of the
finiteness of the multilayers on the Hc2par values. Moreover, the result
depends on the actual symmetry of the system. When the symmetry plane is in
the center of superconductor layer the Hc2par is larger at high temperatures
with respect to the situation when the symmetry plane is in the center of
nonsuperconductor layers.
For superlattices with regular array of antidots we observed the sudden
increase of the critical current at liquid helium lambda point (2.18K). The
absolute value of the jump is function of the sample anisotropy and magnetic
field values. The effect is explained in terms of the increase of the pinning
efficiency at the antidot - multilayer boundary due to the wetting the
antidots below 2.18K.
The results of this work point out the importance of the boundary conditions
on the critical parameters of superconductor - based nanostructures.
