Characterization of ferromagnetic/superconductor heterostructures

The interaction between superconducting (SC) and ferromagnetic (FM) order parameters in hybrid SC/FM heterostructures with laterally nonhomogeneous magnetic field distribution in the FM layer causes a controllable switching of the superconducting nucleation and is measured here using neutron diffraction experiments.

Epitaxial SC/FM heterostructures using Nb and FePd are grown under ultra-high vacuum conditions using molecular beam epitaxy (MBE). Structure and stoichiometry of the samples are investigated using x-ray-diffraction, reflectivity and Rutherford backscattering. The magnetic properties are studied with highly sensitive SQUID magnetometer and magnetic force microscopy. The superconducting critical temperature is determined using PPMS. Neutron diffraction experiments are carried out to investigate the influence of an external magnetic field as well as the influence of the superconducting toplayer on the domain structure of the ferromagnet.

Results here show the grazing incidence small angle neutron scattering (GISANS) image for the FePd layer in different sample orientations to the incident beam. Observed are the specular spot as well as the off-specular scattered signals.

Contact: Annika Stellhorn, Emmanuel Kentzinger

Back to main page