Upper critical magnetic fields in superconductor/ferromagnet hybrids

• Published in: Journal of physics. Condensed matter Vol. 21; no. 25; pp. 254201 - 254201 (3)
• Main Authors: Cirillo, C, Prischepa, S L, Attanasio, C
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Bristol IOP Publishing 24.06.2009; Institute of Physics
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Exact sciences and technology; Mixed state, critical fields, and surface sheath; Multilayers, superlattices , heterostructures; Physics; Properties of type I and type II superconductors; Superconducting films and low-dimensional structures; Superconductivity; Dimensionality; Nickel alloys; Magnetic field effects; Ferromagnetic materials; Critical field; Niobium; Thickness; Interfaces; Superconductors; Palladium alloys; Copper alloys; Transition elements; Heterostructures; Transition element alloys
• ISSN: 0953-8984; 1361-648X
• DOI: 10.1088/0953-8984/21/25/254201

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.