Inhomogeneous vortex distribution and magnetic coupling in oxide superconductor–ferromagnet hybrids

Abstract

Hybrid systems of thin films of oxide ferromagnets and high-temperature superconductors have been investigated by scanning Hall probe microscopy (SHPM) to analyze the local magnetic flux density distribution at low temperatures. In addition to the intrinsic properties of the films themselves, such structures exhibit novel phenomena due to complex interactions arising at the interface between them. The latter can be divided into processes originating from either electronic or magnetic coupling, respectively. As a direct consequence, the distribution of vortices in the superconductor is strongly influenced by the magnetic background arising from the ferromagnet. The local magnetic information obtained from SHPM images provides clear evidence for the presence of a magnetic dipolar interaction between the magnetic domains of the ferromagnetic component and the vortex ensemble in the superconductor.