Superconductivity as a probe of magnetic switching and ferromagnetic stability in Nb/Ni multilayers
The temperature and field dependences of the AC and DC magnetic moment of superconducting and ferromagnetic Nb/Ni multilayers were measured using a SQUID magnetometer with magnetic field applied parallel to the multilayer plane. Periodic kinks in the superconducting upper critical field are evidence...
| Autores: | , , , , , , , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2006 |
| País: | España |
| Institución: | Universidad Complutense de Madrid (UCM) |
| Repositorio: | Docta Complutense |
| Idioma: | inglés |
| OAI Identifier: | oai:docta.ucm.es:20.500.14352/52128 |
| Acceso en línea: | https://hdl.handle.net/20.500.14352/52128 |
| Access Level: | acceso abierto |
| Palabra clave: | 538.9 Layered superconductors Surface-barrier Flux lattices Thin-films Superlattices Temperature Transition Field Resonance Interplay Física de materiales Física del estado sólido 2211 Física del Estado Sólido |
| Sumario: | The temperature and field dependences of the AC and DC magnetic moment of superconducting and ferromagnetic Nb/Ni multilayers were measured using a SQUID magnetometer with magnetic field applied parallel to the multilayer plane. Periodic kinks in the superconducting upper critical field are evidence for nucleation of a hierarchy of Abrikosov vortex lattices aligned parallel to the multilayer. Small cusps in the low-field, isothermal DC magnetization are evidence that supercurrents are sensitive to extremely small changes in the Ni layer magnetization. Smooth ferromagnetic hysteresis is observed in the normal state, but is supplanted below the superconducting transition by two reproducible discontinuities that indicate magnetic switching of the Ni layers is tightly coupled to the supercurrents. The discontinuities are attributed to the non-dipole character of the moment near switching fields and, therefore, cannot be analyzed by standard magnetometer software. Ferromagnetic resonance spectra were measured in parallel and perpendicular DC magnetic fields at room temperature and 4.2 K, and resulting data suggest that Ni layers interact magnetically in the superconducting state. |
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