Persistent half-metallic ferromagnetism in a (111)-oriented manganite superlattice

Abstract

We employ electronic structure calculations to show that a (111)-oriented (LaMnO3)12∣(SrMnO3)6 superlattice retains a half-metallic ferromagnetic character despite its large thickness. We link this behaviour to the strain and the octahedral connectivity between the layers. This also gives rise to breathing modes, which are coupled to charge and spin oscillations, whose components have a pure eg character. Most interestingly, the magnetisation reaches its maximum value inside the LaMnO3 region and not at the interface, which is fundamentally different from what observed for the (001) orientation. The inter-atomic exchange coupling shows that the magnetic order arises from the double-exchange mechanism, despite competing interactions inside the SrMnO3 region. Finally, the van Vleck distortions and the spin oscillations are crucially affected by the variation of Hund’s exchange and charge doping, which allows us to speculate that our system behaves as a Hund’s metal, creating an interesting connection between manganites and nickelates.

Atomic scale interfacial magnetism and origin of metal-insulator transition in (LaNiO$$_3$$)$$_n$$/(CaMnO$$_3$$)$$_m$$ superlattices: a first principles study

“…8. It is worth considering that strained bulk of a very similar compound, LaMnO 3 and SrMnO 3 show very similar behaviour 24 .…”

“…In this respect, perovskites in lower dimensional environments (such as surfaces or interfaces) host phases in competition which may be elusive though. For example, charge vs orbital order, as predicted recently 15,[23][24][25] are difficult to detect, possibly because of the peculiarity of samples. Control and detection of defects is not trivial, and even the detailed formalism of density functional theory (DFT), which has achieved many predictions (e.g.…”

Spacer-layer-tunable ferromagnetic half-metal-ferromagnetic insulator transition in SrVO₃/SrTiO₃ superlattice

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