Proximity of LaOFeAs to a magnetic instability

Abstract

We investigate the effect of external pressure on the Fe magnetic moment in undoped LaOFeAs within the framework of density functional theory and show that this system is close to a magnetic instability: The Fe moment is found to drop by nearly a factor of 3 within a pressure range of $\pm$ 5 GPa around the calculated equilibrium volume. While the Fe moments show an unusually strong sensitivity to the spin arrangement (type of anti-ferromagnetic structure), the low temperature structural distortion is found to have only a minor influence on them. Analysis of the Fermi surface topology and nesting features shows that these properties change very little up to pressures of at least 10 GPa. We discuss the magnetic instability in terms of the itinerancy of this system.

5 pages, 4 figures

References in corpus (15)

• Superconductivity at 38 K in the iron arsenide (Ba1-xKx)Fe2As2
• Magnetic Order versus superconductivity in the Iron-based layered La(O1-xFx)FeAs systems
• LaFeAsO${}_{1-x}$F${}_x$: A low carrier density superconductor near itinerant magnetism
• Origin of the ~150 K Anomaly in LaOFeAs; Competing Antiferromagnetic Superexchange Interactions, Frustration, and Structural Phase Transition
• Superconductivity up to 29 K in SrFe2As2 and BaFe2As2 at high pressures
• Pressure-induced volume-collapsed tetragonal phase of CaFe2As2 as seen via neutron scattering
• Proximity of antiferromagnetism and superconductivity in LaO${}_{1-x}$F${}_x$FeAs: effective Hamiltonian from ab initio studies
• Crystallographic Phase Transition and High-Tc Superconductivity in LaFeAsO:F
• Magnetic and structural transitions in layered FeAs systems: AFe2As2 versus RFeAsO compounds
• Pressure-induced superconductivity in single crystal CaFe2As2
• Structure and Magnetic Order in the NdFeAs(O,F) Superconductor System
• Effect of pressure on the magnetostructural transition in SrFe2As2
• Effect of pressure on the superconducting critical temperature of La[O_{0.89}F_{0.11}]FeAs and Ce[O_{0.88}F_{0.12}]FeAs
• Two pressure-induced transitions in TiOCl: Mott insulator to anisotropic metal
• Microscopic modeling of a spin crossover transition

Cited by in corpus (4)

• Interplay between magnetic properties and Fermi surface nesting in iron pnictides
• Microscopic origin of pressure-induced phase transitions in iron-pnictide $AF{e}_{2}A{s}_2$ superconductors: an {ab initio} molecular-dynamics study
• Tight binding model for iron pnictides
• Pressure effect on superconductivity and magnetism in FeSex