Interfacial antiferromagnetic coupling between SrRuO3 and La0.7S

Engineering exchange interaction between magnetic thin films is a key ingredient for achieving high-performance spintronics devices. In this work, the exchange coupling effect of bilayers consisting of perpendicularly magnetized tetragonal phase $\mathrm{SrRu}{\mathrm{O}}_{3}$ (SRO) and in-plane magnetized $\mathrm{L}{\mathrm{a}}_{0.7}\mathrm{S}{\mathrm{r}}_{0.3}\mathrm{Mn}{\mathrm{O}}_{3}$ has been investigated. We observed an intriguing antiferromagnetic exchange coupling at the interface of such heterostructures with orthogonal magnetic configuration. The unique exchange coupling coexists with the formation of domain walls in the SRO layer as inferred from the magnetometry and magnetotransport measurements, resulting in a positive exchange bias effect. The thickness and temperature dependence of the bias field further confirm the interfacial origin of the antiferromagnetic coupling effect.