AbstractThe observation of magnetic interaction at the interface between nonmagnetic oxides has attracted much attention in recent years. In this report, we show that the Kondo-like scattering at the SrTiO₃-based conducting interface is enhanced by increasing the lattice mismatch and growth oxygen pressure P_O2. For the 26-unit-cell LaAlO₃/SrTiO₃ (LAO/STO) interface with lattice mismatch being 3.0%, the Kondo-like scattering is observed when P_O2 is beyond 1 mTorr. By contrast, when the lattice mismatch is reduced to 1.0% at the (La_0.3Sr_0.7)(Al_0.65Ta_0.35)O₃/SrTiO₃ (LSAT/STO) interface, the metallic state is always preserved up to P_O2 of 100 mTorr. The data from Hall measurement and X-ray absorption near edge structure (XANES) spectroscopy reveal that the larger amount of localized Ti³⁺ ions are formed at the LAO/STO interface compared to LSAT/STO. Those localized Ti³⁺ ions with unpaired electrons can be spin-polarized to scatter mobile electrons, responsible for the Kondo-like scattering observed at the LAO/STO interface.