Oxygen deficiency and cooling field driven vertical hysteretic shift in epitaxial SrRuO3/SrTiO3 heterostructures

SrRuO3 thin films have been epitaxially grown on SrTiO3 substrates using a pulsed laser deposition technique. By adjusting the oxygen partial pressure during deposition, a sharp drop in the Curie temperature ( T C) of 95 K and vertical magnetization shift ( M Shift) of 82.7% in the hysteresis loop was observed due to the oxygen deficiency induced lattice distortion that modifies the strong hybridization of p-d orbitals and perpendicular uniaxial magnetic anisotropy. In particular, the vertical hysteretic shift can also be effectively tuned by the applied cooling field, and thus, we obtained a giant and complete M Shift of 106% with a large volume of pinned Ru4+ moments. These findings reveal the critical role played by intrinsic oxygen defects and extrinsic cooling field in controlling magnetic couplings in this perovskite-type complex oxide system.