Influence of Domain Width on Vortex Nucleation in Superconductor/Ferromagnet Hybrid Structures.

Conference · Sun Mar 15 04:00:00 EDT 2015

DOI:https://doi.org/10.1007/s10948-014-2650-9· OSTI ID:1357459

Iavarone, M.; Moore, S. A.; Fedor, J.; Novosad, V.; Pearson, J. E.; Karapetrov, G.

We have investigated the effect of spatially inhomogenous magnetic fields on vortex nucleation in magnetically coupled superconductor/ferromagnet hybrid structures. Using low-temperature scanning tunneling microscopy and spectroscopy (LT-STM/STS) we have studied Pb/[Co-Pd] systems with slightly inhomogeneous magnetic domain width throughout the sample. Visualization of the underlying magnetic template structure is achieved through field dependent conductance maps. In the case of zero applied fields, these maps reveal the absence of vortices below a threshold domain width. At those locations with insufficient domain width to support generation of vortices in zero applied fields, nucleation can be restored through the application of an external magnetic field, with vortices nucleating above the domain parallel to the external field. For the magnetic domain width studied in this work, local tunneling spectroscopy reveals uniform superconducting critical temperature as a function of location, despite of local differences in the stray field experienced by the superconductor.

• Research Organization: Argonne National Laboratory (ANL)
• Sponsoring Organization: USDOE Office of Science - Office of Basic Energy Sciences - Materials Sciences and Engineering Division
• DOE Contract Number: AC02-06CH11357
• OSTI ID: 1357459
• Country of Publication: United States
• Language: English

Related Subjects

Low Temperature Superconductors
Superonductor - Ferromagnet Hybrids
Vortices and Nanostructured Superconductors