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Spin Polarization-Assisted Dopant Segregation at a Coherent Phase Boundary
Yixiao Jiang1,2, Hongping Li3,4, Tingting Yao1,2
1Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China.
ACS Nano
|December 8, 2021
Summary
Unexpected W atom segregation occurs at coherent Fe3O4/Fe2O3 phase boundaries. Spin-polarized oxygen atoms drive this impurity trapping, offering new ways to tailor magnetic material properties.
Area of Science:
- Materials Science
- Physics
- Chemistry
Background:
- Coherent phase boundaries are typically considered impurity-free due to low interfacial energy.
- Previous understanding suggested no impurity segregation at such boundaries.
Purpose of the Study:
- To investigate impurity segregation at coherent Fe3O4/Fe2O3 phase boundaries.
- To understand the role of spin polarization in dopant behavior at interfaces.
Main Methods:
- Comparative analysis of pristine and W-doped Fe3O4/Fe2O3 phase boundaries.
- Investigation of atomic structure and electronic properties at the interface.
Main Results:
- Equilibrium segregation of Tungsten (W) atoms observed at coherent Fe3O4 (111)/Fe2O3 (0001) phase boundaries.
- Spin-polarized oxygen atoms with large magnetic moments identified at the pristine interface.
- W atoms selectively substitute Fe atoms, neutralizing the magnetic moments of interfacial oxygen atoms.
Conclusions:
- Coherent phase boundaries can trap impurities, challenging prior assumptions.
- Local spin polarization is a key driving force for dopant segregation at interfaces.
- Elemental doping offers an effective strategy for tuning the properties of magnetic materials and devices.
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