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Updated: Sep 19, 2025
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Tuning Oxide Properties by Oxygen Vacancy Control During Growth and Annealing
Published on: June 9, 2023
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Eu3Ta2ON5: an n = 2 Ruddlesden-Popper ferromagnetic oxynitride with long-range ordered anion vacancies
Judith Oró-Solé1, Jhonatan Ricardo Guarín1, Carlos Frontera1
1Institut de Ciència de Materials de Barcelona (ICMAB-CSIC), Campus UAB, 08193 Bellaterra, Spain. amparo.fuertes@icmab.es.
Dalton Transactions (Cambridge, England : 2003)
|June 19, 2025
Summary
A new europium tantalum oxynitride, Eu3Ta2ON5, with a Ruddlesden-Popper structure was synthesized. This material exhibits ferromagnetic ordering below 20 K, significantly higher than related compounds, due to enhanced superexchange interactions.
Area of Science:
- Materials Science
- Solid-State Chemistry
- Inorganic Chemistry
Background:
- Ruddlesden-Popper phases are known for their interesting structural and magnetic properties.
- Oxynitrides offer unique electronic and magnetic characteristics compared to oxides.
- Ternary europium compounds are explored for their magnetic ordering phenomena.
Purpose of the Study:
- To synthesize and characterize a new oxynitride compound with a Ruddlesden-Popper structure.
- To investigate the structural, electronic, and magnetic properties of Eu3Ta2ON5.
- To understand the origin of ferromagnetic ordering and its relation to structure.
Main Methods:
- Solid-state reaction synthesis at high temperatures under nitrogen atmosphere.
- X-ray diffraction for crystal structure determination (space group I4/mmm).
- Electron Energy Loss Spectroscopy (EELS) for valence state analysis.
- Magnetic susceptibility measurements to determine magnetic ordering temperature (Curie temperature, Tc).
Main Results:
- Successful synthesis of Eu3Ta2ON5 with n=2 Ruddlesden-Popper structure.
- Crystallographic data: a = 3.98240(1) Å, c = 20.42020(6) Å.
- Mixed Eu2+/Eu3+ valence observed, with Eu3+ predominantly in 8-coordinated sites.
- Ferromagnetic ordering of Eu2+ ions below Tc = 20 K.
- Higher Tc compared to related titanate Ruddlesden-Popper compounds.
Conclusions:
- Eu3Ta2ON5 is a novel oxynitride with a layered structure.
- The enhanced Curie temperature is attributed to covalency-reinforced Eu2+-N/O-Eu2+ superexchange interactions.
- This study highlights the potential of oxynitrides in tuning magnetic properties.
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