2008/09/01 by J. J. Pulikkotil, Liqin Ke, Pulikkotil, J. J. +7
Materials Science · Physics and Astronomy · #FOS: Physical sciences #Iron-based superconductors research #Materials Science (cond-mat.mtrl-sci) #Rare-earth and actinide compounds #Superconductivity (cond-mat.supr-con)
paper · pdf · doi:10.48550/arxiv.0809.0283
openalex publication_date 2008/09/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/01
Using linear-response density-functional theory, we obtain the magnetic interactions in the several iron pnictides. The ground state has been found to be non-collinear in FeSe, with a large continuum of nearly degenerate states lying very close to the magnetic "striped" structure. The presence of non-collinearity also seems to be a generic feature of iron pnictides when the Fe moment is small. At small RFe-Se the system is itinerant: strong frustration give rise to excess of spin entropy, long ranged interactions create incommensurate orderings and strong biquadratic (or ring) couplings violate the applicability of Heisenberg model. There is a smooth transition to more localized behavior as RFe-Se increases: stable magnetic orbital order develops which favor long range AFM stripe ordering with strongly anisotropic in-plane exchange couplings. The stabilization of the stripe magnetic order is accompanied by the inversion of the exchange coupling.