In search for the superconducting spin-switch: Magnetization induced resistance switching effects in La$_{0.67}$Sr$_{0.33}$MnO$_{3}$/Yba$_{2}$Cu$_{3}$O$_{7-\delta }$ bi- and trilayers

The influence of the magnetization on the superconducting $T_{c}$ in bi- and trilayers consisting of the half-metallic ferromagnet La$_{0.67}$Sr$_{0.33}$MnO$_{3}$ and the high-temperature superconductor YBa$_{2}$Cu$_{3}$O$_{7-\delta }$ is studied. Interfaces that are partly oriented within the crystallographic ab-plane are achieved by tilted epitaxial growth on SrTiO$_{3}$ (305) substrates. Sharp magnetization switching behavior is observed in the (305) oriented structures, due to the uniaxial magnetic anisotropy. At temperatures close to $T_{c}$, resistance jumps are induced by magnetization switching. Our results indicate that the switching behavior arises from magnetic stray fields from the ferromagnetic layers that penetrate into the superconductor, rather than spin-switch or spin-accumulation effects.