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Growth and Electrostatic/chemical Properties of Metal/LaAlO3/SrTiO3 Heterostructures
Published on: February 8, 2018
Titanium dxy ferromagnetism at the LaAlO3/SrTiO3 interface
1Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA. jslee@slac.stanford.edu
Nature Materials
|June 4, 2013
Summary
Ferromagnetism in LaAlO3/SrTiO3 heterostructures originates from Ti(3+) ions at the interface. Spectroscopic studies reveal in-plane magnetic order, highlighting emergent phenomena in oxide interfaces.
Area of Science:
- Condensed matter physics
- Materials science
- Oxide interfaces
Background:
- Ferromagnetism observed in LaAlO3/SrTiO3 heterostructures is unexpected, as constituent materials lack bulk ferromagnetism.
- Previous studies indicated ferromagnetism but did not identify the magnetic host.
Purpose of the Study:
- To spectroscopically identify the origin of magnetism in LaAlO3/SrTiO3 heterostructures.
- To elucidate the electronic and orbital character of the magnetic centers.
Main Methods:
- Element-specific X-ray magnetic circular dichroism (XMCD).
- X-ray absorption spectroscopy (XAS).
- Theoretical model calculations.
Main Results:
- Direct evidence for in-plane ferromagnetic order at the interface.
- Identification of Ti(3+) ions as the source of magnetism.
- Magnetism localized to the dxy orbital of the anisotropic t2g band.
Conclusions:
- The study confirms Ti(3+) ions in specific orbitals are responsible for ferromagnetism at the oxide interface.
- Highlights emergent magnetic phenomena at oxide interfaces, distinct from bulk properties.
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