title: Upper critical magnetic fields in superconductor/ferromagnet hybrids.
abstract: We measured parallel upper critical magnetic fields in Nb/PdNi and Nb/CuNi bilayers and Nb/PdNi/Nb and Nb/CuNi/Nb trilayers. In the bilayers case the measurements reveal a dependence of the reduced two-dimensional-three-dimensional crossover temperature, t(cr) = T(cr)/T(c), on the different values of the superconductor (S)/ferromagnet (F) interface transparencies. In the case of the trilayers we observe that the reduced crossover temperature as a function of the ferromagnetic layer thickness, d(F), reaches a value equal to one only when the π-phase occurs in these systems. Also in this case the influence of the interface transparency on the observed results is discussed.
authors.affiliation: Laboratorio Regionale SuperMat, CNR-INFM Salerno, Salerno I-84081, Italy. Dipartimento di Fisica 'E R Caianiello', Università degli Studi di Salerno, Baronissi, Salerno I-84081, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Cirillo
authors.forename: S L
authors.initials: SL
authors.lastname: Prischepa
authors.forename: C
authors.initials: C
authors.lastname: Attanasio