Preparation And Physical Properties Study For SrRuO₃/SrIrO₃ Superlattices

The heterostructure interface provides a powerful platform for exploring rich emergent phenomena,such as interfacial superconductivity and two-dimensional electron gas.Here,epitaxial SrRuO3/SrIrO3 superlattices were successfully synthesized on chemically etched(001)-SrTiO3 substrates with TiO2 as terminated surface by PLD.The structure and morphology of these superlattices were characterized,and the magnetic,electron transport and magneto-transport properties were measured.The orthorhombic structures of the SrRuO3 and the SrIrO3 layers,as well as good epitaxy are confirmed by the XRD patterns and further verified by the selected area electron diffraction(SAED)patterns.AFM and TEM results indicate that all of these samples have smooth surfaces and distinct flat interfaces and there is no obviously atomic dffusion at the interfaces,two-dimensional growth model terraces are also demonstrated.All these samples display a metal-semiconductor transition at low temperature(about 50 K).The upturn of resistance at low-temperature may come from two contributions,one is the enhanced scattering coming from the spin glass freezing,the other is the weak localization.The MR curves show a typically butterfly-like feature,indicating the competition of negative MR of magnetism and weak anti-localization due to spin-orbit interaction at low temperature.Magnetic properties measurements show a broad cusp-type splitting in temperature-dependent magnetization under the zero-field-cooling/field-cooling conditions,and magnetization relaxation follows the modified Stretch function model,and double hysteresis magnetization loops.These results suggest the coexistence of interfacial spin-glass and ferromagnetic ordering in the superlattices.In addition,the topological Hall efect was observed at low temperatures,and it is weakened with the increase of the SrIrO3 layer thickness.These results maybe suggest that a non-coplanar spin texture is generated at the SrRuO3/SrIrO3 interfaces due to the interfacial Dzyaloshinskii-Moriya interaction.This work demonstrates that SrIrO3 can effectively indvce interfacial Dzyaloshinskii-Moriya interactions in superlattices,which may be useful for developing spintronic devices based on perovskite oxides.