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Removal of the Magnetic Dead Layer by Geometric Design
Author(s) -
Guo ErJia,
Roldan Manuel A.,
Charlton Timothy,
Liao Zhaoliang,
Zheng Qiang,
Ambaye Haile,
Herklotz Andreas,
Gai Zheng,
Ward T. Zac,
Lee Ho Nyung,
Fitzsimmons Michael R.
Publication year - 2018
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.201800922
Subject(s) - manganite , materials science , neutron reflectometry , magnetization , ferromagnetism , magnetism , condensed matter physics , exchange bias , scanning transmission electron microscopy , heterojunction , transmission electron microscopy , magnetic anisotropy , nanotechnology , neutron scattering , optoelectronics , scattering , optics , magnetic field , physics , quantum mechanics , small angle neutron scattering
Abstract The proximity effect is used to engineer interface effects such as magnetoelectric coupling, exchange bias, and emergent interfacial magnetism. However, the presence of a magnetic “dead layer” adversely affects the functionality of a heterostructure. Here, it is shown that by utilizing (111) polar planes, the magnetization of a manganite ultrathin layer can be maintained throughout its thickness. Combining structural characterization, magnetometry measurements, and magnetization depth profiling with polarized neutron reflectometry, it is found that the magnetic dead layer is absent in the (111)‐oriented manganite layers, however, it occurs in the films with other orientations. Quantitative analysis of local structural and elemental spatial evolutions using scanning transmission electron microscopy and electron energy loss spectroscopy reveals that atomically sharp interfaces with minimal chemical intermixing in the (111)‐oriented superlattices. The polar discontinuity across the (111) interfaces inducing charge redistribution within the SrTiO 3 layers is suggested, which promotes ferromagnetism throughout the (111)‐oriented ultrathin manganite layers. The approach of eliminating problematic magnetic dead layers by changing the crystallographic orientation suggests a conceptually useful recipe to engineer the intriguing physical properties of oxide interfaces, especially in low dimensionality.