Charge transfer driving interfacial reconstructions in perovskite oxide heterostructures

Charge transfer in perovskite oxide heterostructures could break the delicate balance among charge, spin, orbital and lattice order at the interface, producing exotic phenomena that cannot be observed in bulk materials. Here, the authors observe an opposite charge transfer direction in two 3d/5d perovskite oxide heterostructures SrIrO3/LaNiO3 and SrIrO3/NdNiO3, investigate the triggered interfacial orbital and lattice reconstructions, and discuss their manipulation on transport and magnetic characteristics. Charge transfer in perovskite oxide heterostructures could break the delicate balance among charge, spin, orbital and lattice order at the interface, producing exotic phenomena that cannot be observed in bulk materials. Here, opposite interfacial charge transfer directions are observed in SrIrO3/NdNiO3 and SrIrO3/LaNiO3 3d/5d perovskite heterostructures. This is accompanied with an inverse change of Ni e(g) orbital polarization and Ni-O pd hybridization across the interface, by stretching/compressing the out-of-plane Ni-O bond in the opposite internal electrical field due to the opposite electron transfer direction. These interfacial reconstructions finally bring about a manipulation on the transport and magnetic characteristics. This work reveals that A site cation in perovskite heterostructures could be a knob to control the interfacial charge transfer direction, and the 3d/5d perovskite interfaces are excellent platform to study the complex interplay between various order parameters and stimulate novel interfacial effects.

Automated summary

Charge transfer in perovskite oxide heterostructures can disrupt the delicate balance among charge, spin, orbital, and lattice order at the interface, resulting in exotic phenomena not seen in bulk materials. The authors observed opposite charge transfer directions in two 3d/5d perovskite oxide heterostructures (SrIrO3/LaNiO3 and SrIrO3/NdNiO3), investigated the resulting interfacial orbital and lattice reconstructions, and discussed their effects on transport and magnetic characteristics.