Exceptional field dependence of antiferromagnetic magnons in LiFePO4

• Verfasst von: Werner, Johannes [VerfasserIn]
• Verfasst von: Neef, Christoph [VerfasserIn]
• Verfasst von: Koo, Changhyun [VerfasserIn]
• Verfasst von: Ponomaryov, Alexey N. [VerfasserIn]
• Verfasst von: Zvyagin, Sergei [VerfasserIn]
• Verfasst von: Klingeler, Rüdiger [VerfasserIn]
• Titel: Exceptional field dependence of antiferromagnetic magnons in LiFePO4
• Verf.angabe: J. Werner, C. Neef, C. Koo, A. Ponomaryov, S. Zvyagin, and R. Klingele
• E-Jahr: 2021
• Jahr: 5 May 2021
• Umfang: 7 S.
• Fussnoten: Im Titel die "4" ist tiefgestellt ; Gesehen am 09.06.2021
• Titel Quelle: Enthalten in: Physical review
• Ort Quelle: Woodbury, NY : Inst., 2016
• Jahr Quelle: 2021
• Band/Heft Quelle: 103(2021), 17, Artikel-ID 174406, Seite 1-7
• ISSN Quelle: 2469-9969
• DOI: doi:10.1103/PhysRevB.103.174406
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1760109495

Abstract

Low-energy magnon excitations in magnetoelectric LiFePO4 have been investigated by high-frequency-high-field electron spin resonance spectroscopy in magnetic fields up to B=58T and frequencies up to f=745GHz. For magnetic fields applied along the easy magnetic axis, the excitation gap softens and vanishes at the spin-flop field of BSF=32T before hardening again at higher fields. In addition, for B≲BSF we observe a resonance mode assigned to excitations due to Dzyaloshinskii-Moriya (DM) interactions, thereby evidencing a sizable DM interaction of ≈150μeV in LiFePO4. Both the magnetization and the excitations up to high magnetic fields are described in terms of a mean-field theory model which extends recent zero-field inelastic neutron scattering results. Our results imply that magnetic interactions as well as magnetic anisotropy have a sizable quadratic field dependence which we attribute to significant magnetostriction.