Origin of the 150-K Anomaly in LaFeAsO: Competing Antiferromagnetic Interactions, Frustration, and a Structural Phase Transition

Published

August 1, 2008

Author(s)

Taner N. Yildirim

Abstract

From all-electron fixed-spin-moment calculations we show that ferromagnetic and checkerboard antiferromagnetic ordering in LaFeAsO are not stable and the stripe antiferromagnetic configuration with is the only stable ground state. The main exchange interactions between Fe ions are large, antiferromagnetic, and frustrated. The magnetic stripe phase breaks the tetragonal symmetry, removes the frustration, and causes a structural distortion. These results successfully explain the magnetic and structural phase transitions in LaFeAsO recently observed by neutron scattering. The presence of competing strong antiferromagnetic exchange interactions suggests that magnetism and superconductivity in doped LaFeAsO may be strongly coupled, much like in the high- cuprates.

Citation

Physical Review Letters

Issue

5

Pub Type

Journals

Download Paper

https://doi.org/10.1103/PhysRevLett.101.057010

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Keywords

Supercondcutivity, magnetism, frustration, structural phase transition

Citation

Yildirim, T. (2008), Origin of the 150-K Anomaly in LaFeAsO: Competing Antiferromagnetic Interactions, Frustration, and a Structural Phase Transition, Physical Review Letters, [online], https://doi.org/10.1103/PhysRevLett.101.057010, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=610067 (Accessed October 10, 2025)