Abstract
Heterostructures of strongly correlated oxides demonstrate various intriguing and potentially useful interfacial phenomena. LaMnO3/SrMnO3 superlattices are presented showcasing a new high-temperature ferromagnetic phase with Curie temperature, TC ≈360 K, caused by electron transfer from the surface of the LaMnO3 donor layer into the neighboring SrMnO3 acceptor layer. As a result, the SrMnO3 (top)/LaMnO3 (bottom) interface shows an enhancement of the magnetization as depth-profiled by polarized neutron reflectometry. The length scale of charge transfer, λTF ≈2 unit cells, is obtained from in situ growth monitoring by optical ellipsometry, supported by optical simulations, and further confirmed by high resolution electron microscopy and spectroscopy. A model of the inhomogeneous distribution of electron density in LaMnO3/SrMnO3 layers along the growth direction is concluded to account for a complex interplay between ferromagnetic and antiferromagnetic layers in superlattices.
Original language | English |
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Article number | 1808270 |
Journal | Advanced Functional Materials |
Volume | 30 |
Issue number | 18 |
DOIs | |
State | Published - 1 May 2020 |
Keywords
- charge transfer
- interfaces
- interfacial ferromagnetism
- oxide superlattices