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Published on: March 24, 2019
Unprecedented robust antiferromagnetism in fluorinated hexagonal perovskites
Mihai Sturza1, Houria Kabbour, Sylvie Daviero-Minaud
1Université Lille Nord de France, UCCS, CNRS UMR 8181, ENSCL-USTL, Villeneuve d'Ascq, France.
Journal of the American Chemical Society
|June 9, 2011
Summary
Introducing fluorine into hexagonal perovskites significantly boosts antiferromagnetic (AFM) ordering. This enhancement, reaching near 700 K, is crucial for developing robust AFM materials for spintronics applications.
Area of Science:
- Solid State Chemistry
- Materials Science
- Magnetism
Background:
- Antiferromagnetic (AFM) oxides with high Néel temperatures are essential for spintronics, including exchange bias and multiferroics.
- Hexagonal perovskites (HP) typically exhibit weaker magnetic exchange due to face-sharing octahedra compared to corner-sharing structures.
Purpose of the Study:
- To investigate the effect of partial fluorine (F-) substitution in iron-based hexagonal perovskites (HP).
- To enhance the antiferromagnetic ordering and Néel temperature (T(N)) in these materials for potential spintronic applications.
Main Methods:
- Experimental synthesis and characterization of fluorine-substituted iron-based hexagonal perovskites.
- Ab initio calculations to support experimental findings and elucidate the underlying mechanisms.
Main Results:
- Partial introduction of F- into Fe-based HP significantly increases antiferromagnetic ordering.
- Achieved Néel temperatures (T(N)) approach ≈ 700 K, among the highest reported for iron oxides.
- Fluorine substitution induces structural changes and chemical reduction to Fe(3+), enhancing magnetic exchange.
Conclusions:
- Aliovalent F- for O(2-) substitution in preferred anionic sites is key to boosting T(N) in HPs.
- The study demonstrates a viable strategy to engineer high-performance antiferromagnetic materials for advanced technologies.
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