Weak spin interactions in Mott insulating La2O2Fe2OSe2

McCabe, E.E.; Stock, C.; Rodriguez, E.E.; Wills, A.S.; Taylor, J.W.; Evans, J.S.O.

Abstract

Identifying and characterizing the parent phases of iron-based superconductors is an important step towards understanding the mechanism for their high-temperature superconductivity. We present an investigation into the magnetic interactions in the Mott insulator La2O2Fe2OSe2. This iron oxyselenide adopts a 2-k magnetic structure with low levels of magnetic frustration. This magnetic ground state is found to be dominated by next-nearest-neighbor interactions J2 and J2′ and the magnetocrystalline anisotropy of the Fe2+ site, leading to 2D-Ising-like spin S=2 fluctuations. In contrast to calculations, the values are small and confine the spin excitations below ∼25 meV. This is further corroborated by sum rules of neutron scattering. This indicates that superconductivity in related materials may derive from a weakly coupled and unfrustrated magnetic structure.

Citation

McCabe, E., Stock, C., Rodriguez, E., Wills, A., Taylor, J., & Evans, J. (2014). Weak spin interactions in Mott insulating La2O2Fe2OSe2. Physical review B, 89(10), Article 100402(R). https://doi.org/10.1103/physrevb.89.100402

• Journal Article Type: Article
• Publication Date: Mar 10, 2014
• Deposit Date: Jun 15, 2014
• Publicly Available Date: Jun 16, 2014
• Journal: Physical review B - Condensed Matter and Materials Physics
• Print ISSN: 1098-0121
• Electronic ISSN: 1550-235X
• Publisher: American Physical Society
• Peer Reviewed: Peer Reviewed
• Volume: 89
• Issue: 10
• Article Number: 100402(R)
• DOI: https://doi.org/10.1103/physrevb.89.100402
• Public URL: https://durham-repository.worktribe.com/output/1449985