Europhys. Lett., 60 (2) , pp. 295-301 (2002)
Increase of the critical current at the liquid-helium lambda point in superconducting perforated multilayersS. L. Prischepa1, 2, L. V. Mercaldo1, C. Attanasio1, M. Salvato1, L. Maritato1, 3 and S. Barbanera4
1 Dipartimento di Fisica "E. R. Caianiello" and INFM Università degli Studi di Salerno - Baronissi (Salerno), I-84081, Italy
2 State University of Informatics and Radio Electronics P.Brovka street 6, Minsk 220013, Belarus
3 Dipartimento di Fisica, Università degli Studi di Cagliari Cagliari, I-09042, Italy
4 IESS-CNR - Via Cineto Romano 42, Roma, I-00100, Italy
(Received 28 February 2002; accepted in final form 26 July 2002)
Pinning properties of multilayers with regular array of antidots have been studied at different temperatures in perpendicular magnetic field. The presence of antidots causes a sudden increase (jump) of the critical current at the liquid-helium lambda point ( T=2.18 ). The jump value is a function of magnetic field and sample anisotropy. The hypothesis of liquid helium wetting the antidots below 2.18 , and then inducing a larger pinning efficiency, is put forward.
74.60.Ge - Flux pinning, flux creep, and flux-line lattice dynamics.
74.80.Dm - Superconducting layer structures: superlattices, heterojunctions, and multilayers.
© EDP Sciences 2002