Emergent ferromagnetism with tunable perpendicular magnetic anisotropy in short-periodic SrIrO3/SrRuO3 superlattices

Interface engineering is a promising method to trigger emergent magnetic order in oxide heterostructures. Here, we report on the electrical and magnetic properties of short-periodic superlattices (SLs) (SrIrO3)(n)/(SrRuO3)(n) (n=1-5) epitaxially grown on the (001)-oriented SrTiO3 substrate. Intriguingly, (SrIrO3)(n)/(SrRuO3)(n) superlattices show itinerant ferromagnetism with recovered Curie temperature and magnetic mom3). Moreover, perpendicular magnetic anisotropy (PMA) is observed and can be tuned by the layer thickness n in the superlattices. Enhanced PMA as high as 1.6x106 erg/cm(3) is obtained in the n=1 superlattice, which is considerably higher compared to that in n=4 and 5 SLs. Our systematic thickness-dependent studies reveal that the (SrIrO3)/(SrRuO3) interface plays a crucial role in both electrical and magnetic properties. These results indicate n as a knob to tune the PMA of superlattices, paving a way to design functional materials in transition metal oxides.