Raphaël Aeschlimann, Manuel Bibes, Alexandre Gloter
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引用次数: 0
Abstract
Perovskite rare‐earth titanates RTiO3 display a rich array of magnetic and electronic properties, with a Mott‐insulating ground state and ferro‐ or antiferromagnetic spin orders depending on the rare‐earth R. The nominal Ti valence is 3+ with a corresponding 3d1 configuration. Yet, at the surface of both bulk and thin films of RTiO3, the Ti valence has been found to strongly deviate towards the more stable 4+ state, adversely affecting magnetic properties. While this finding is rather ubiquitous, its exact origin is still poorly understood, which hampers the integration of RTiO3 into complex heterostructures harnessing their rich physics. Here, scanning transmission electron microscope and electron energy loss spectroscopy experiments are used to analyze the top part of an epitaxial DyTiO3 thin film displaying a well‐developed Ti4+‐rich layer over several nanometres. It shows that this valence evolution is related to a combination of short‐range ordered interstitial oxygen planes and Ti‐Dy cationic imbalance. Both defects synergistically contribute to enough hole doping for a complete transition toward Ti4+ over a few unit‐cells from the surface while a structure primarily of the perovskite‐type is maintained.
期刊介绍:
Advanced Materials Interfaces publishes top-level research on interface technologies and effects. Considering any interface formed between solids, liquids, and gases, the journal ensures an interdisciplinary blend of physics, chemistry, materials science, and life sciences. Advanced Materials Interfaces was launched in 2014 and received an Impact Factor of 4.834 in 2018.
The scope of Advanced Materials Interfaces is dedicated to interfaces and surfaces that play an essential role in virtually all materials and devices. Physics, chemistry, materials science and life sciences blend to encourage new, cross-pollinating ideas, which will drive forward our understanding of the processes at the interface.
Advanced Materials Interfaces covers all topics in interface-related research:
Oil / water separation,
Applications of nanostructured materials,
2D materials and heterostructures,
Surfaces and interfaces in organic electronic devices,
Catalysis and membranes,
Self-assembly and nanopatterned surfaces,
Composite and coating materials,
Biointerfaces for technical and medical applications.
Advanced Materials Interfaces provides a forum for topics on surface and interface science with a wide choice of formats: Reviews, Full Papers, and Communications, as well as Progress Reports and Research News.