Dresden 2020 – wissenschaftliches Programm

Die DPG-Frühjahrstagung in Dresden musste abgesagt werden! Lesen Sie mehr ...

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

TT: Fachverband Tiefe Temperaturen

TT 46: Poster Session: Frustrated Magnets, Quantum Magnets, Charge Order and Complex Oxids

TT 46.20: Poster

Mittwoch, 18. März 2020, 15:00–19:00, P2/2OG

Low Energy Spin Excitations of LiFePO4 — •Johannes Werner1, Christoph Neef1, Sergei Zvyagin2, Alexey Ponomaryov2, and Rüdiger Klingeler11Kirchhoff Institute for Physics, Heidelberg University, Heidelberg, Germany — 2High Magnetic Field Laboratory, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany

Spin excitations in single crystalline antiferromagnetic LiFePO4 have been investigated by high-frequency electron spin resonance studies in static and pulsed fields up to 50 T. Several resonance branches are observed, which can be associated with the antiferromagnetic resonance (AFMR) modes as well as with single-ion-like excitations of iron ions at the lithium position (i.e., antisite disorder). Pulsed-field ESR experiments in magnetic fields parallel to the easy b-axis clearly show closing of the AFM gap at the spin-reorientation transition at 32 T, previously observed by pulsed magnetisation measurements [1]. The pronounced curvature of the AFM resonance mode cannot be explained in a conventional two-sublattice mean field model. In addition to the AFMR branches, a less intense linear resonance branch is observed in pulsed fields. Its extrapolated zero field splitting fits well to an excitation which a recent neutron study [2] associates to a single-ion-like transition between excited (i.e., non-ground state) CF-split states. Our data however exclude this scenario but we attribute it to the presence of antisite disorder.
[1] J. Werner et al. PRB 99.21: 214432 (2019)
[2] Y. Yiu et al PRB 95.10: 104409 (2017)

100% | Mobil-Ansicht | English Version | Kontakt/Impressum/Datenschutz
DPG-Physik > DPG-Verhandlungen > 2020 > Dresden