Role of polar compensation in interfacial ferromagnetism of LaNiO${}_3$/CaMnO${}_3$ superlattices

Abstract

Polar compensation can play an important role in the determination of interfacial electronic and magnetic properties in oxide heterostructures. Using x-ray absorption spectroscopy, x-ray magnetic circular dichroism, bulk magnetometry, and transport measurements, we find that interfacial charge redistribution via polar compensation is essential for explaining the evolution of interfacial ferromagnetism in LaNiO${}_3$/CaMnO${}_3$ superlattices as a function of LaNiO${}_3$ layer thickness. In insulating superlattices (4 unit cells or less of LaNiO${}_3$), magnetism is dominated by Ni-Mn superexchange, while itinerant electron-based Mn-Mn double-exchange plays a role in thicker metallic superlattices. X-ray magnetic circular dichroism and resonant x-ray scattering show that Ni-Mn superexchange contributes to the magnetization even in metallic superlattices. This Ni-Mn superexchange interaction can be explained in terms of polar compensation at the LaNiO${}_3$-CaMnO${}_3$ interface. These results highlight the different mechanisms responsible for interfacial ferromagnetism and the importance of understanding compensation due to polar mismatch at oxide-based interfaces when engineering magnetic properties.

8 pages, 5 figures

References in corpus (5)

• Local electronic structure and magnetic properties of LaMn0.5Co0.5O3 studied by x-ray absorption and magnetic circular dichroism spectroscopy
• Electronic reconstruction at SrMnO3-LaMnO3 superlattice interfaces
• Polar catastrophe in ultra-thin limit: A case of rare-earth perovskite LaNiO3
• Onset of metallic behavior in strained (LaNiO3)n/(SrMnO3)2 superlattices
• Atomically flat interface between a single-terminated LaAlO3 substrate and SrTiO3 thin film is insulating

Cited by in corpus (4)

• Relationship between charge redistribution and ferromagnetism at the heterointerface between perovskite oxides LaNiO${}_3$ and LaMnO${}_3$
• Tuning Interfacial Ferromagnetism in LaNiO${}_3$/CaMnO${}_3$ Superlattices by Stabilizing Non-Equilibrium Crystal Symmetry
• Emergent c-axis magnetic helix in manganite-nickelate superlattices
• Emergent phenomena at oxide interfaces studied with standing-wave photoelectron spectroscopy