Strongly two-dimensional exchange interactions in the in-plane metallic antiferromagnet Fe2As probed by inelastic neutron scattering

Manohar H. Karigerasi, Kisung Kang, Garrett E. Granroth, Arnab Banerjee, Andr+¬ Schleife, Daniel P. Shoemaker

Research output: Contribution to journalArticlepeer-review

4 Scopus citations

Abstract

To understand spin interactions in materials of the Cu2Sb structure type, inelastic neutron scattering of Fe2As single crystals was examined at different temperatures and incident neutron energies. The experimental phonon spectra match well with the simulated phonon spectra obtained from density functional theory (DFT) calculations. The measured magnon spectra were compared to the simulated magnon spectra obtained via linear spin wave theory with the exchange coupling constants calculated using the spin polarized, relativistic Korringa-Kohn-Rostoker method in Zhang et al. [Inorg. Chem. 52, 3013 (2013)INOCAJ0020-166910.1021/ic3024716]. The simulated magnon spectra broadly agree with the experimental data although the energy values are underestimated along the K direction. Exchange coupling constants between Fe atoms were refined by fits to the experimental magnon spectra, revealing stronger nearest-neighbor Fe1-Fe1 exchange coupling than previously reported. The strength of this exchange coupling is almost an order of magnitude higher than other exchange interactions despite the three-dimensional nature of the phonon interactions. The lack of scattering intensity at energies above 60 meV makes unconstrained determination of the full set of exchange interactions difficult, which may be a fundamental challenge in metallic antiferromagnets.

Original languageEnglish
Article number114416
JournalPhysical Review Materials
Volume4
Issue number11
DOIs
StatePublished - Nov 20 2020

Funding

This work was undertaken as part of the Illinois Materials Research Science and Engineering Center, supported by the National Science Foundation MRSEC program under NSF Award No. DMR-1720633. The characterization was carried out in part in the Materials Research Laboratory Central Research Facilities, University of Illinois. This work made use of the Illinois Campus Cluster, a computing resource that is operated by the Illinois Campus Cluster Program (ICCP) in conjunction with the National Center for Supercomputing Applications (NCSA) and which is supported by funds from the University of Illinois at Urbana-Champaign. This research is part of the Blue Waters sustained-petascale computing project, which is supported by the National Science Foundation (Awards No. OCI-0725070 and No. ACI-1238993) and the state of Illinois. Blue Waters is a joint effort of the University of Illinois at Urbana-Champaign and its National Center for Supercomputing Applications. This research used resources of the Spallation Neutron Source, a DOE Office of Science User Facility operated by Oak Ridge National Laboratory, and the Advanced Photon Source, a DOE Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357. The authors thank Yan Wu, Huibo Cao, and Douglas Abernathy for helpful discussions regarding the experiment.

Fingerprint

Dive into the research topics of 'Strongly two-dimensional exchange interactions in the in-plane metallic antiferromagnet Fe2As probed by inelastic neutron scattering'. Together they form a unique fingerprint.

Cite this