Dresden 2020 – wissenschaftliches Programm
Die DPG-Frühjahrstagung in Dresden musste abgesagt werden! Lesen Sie mehr ...
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
MA: Fachverband Magnetismus
MA 42: Posters Magnetism I
MA 42.20: Poster
Mittwoch, 18. März 2020, 15:00–18:00, P3
Finite size effects on the ultrafast remagnetization- and lattice dynamics of FePt — Alexander von Reppert1, Lisa Willig1, Jan-Etienne Pudell1, Steffen Zeuschner1,2, Gabriel Sellge3,4, Fabian Ganss3, Olav Hellwig3,4, Jon Ander Arregi5, Voitech Uhlíř5, Aurelien Crut6, and •Matias Bargheer1,2 — 1Institut für Physik und Astronomie, Universität Potsdam, Potsdam — 2Helmholtz-Zentrum Berlin, Berlin — 3Institut für Physik, TU Chemnitz, Chemnitz — 4Helmholtz-Zentrum Dresden-Rossendorf, Dresden — 5CEITEC BUT, Brno University of Technology, Brno, Czechia — 6ILM, Université de Lyon, Villeurbanne, France
We investigate the coupling between the ultrafast lattice and magnetization dynamics of FePt in the L10 phase after an optical heating pulse, as used in heat assisted magnetic recording. We compare continuous and nano-granular thin films and emphasize the impact of the finite size on both the strain response and the remagnetization dynamics. Our timeresolved MOKE experiments show that the remagnetization dynamics for the single-domain FePt nanograins is dictated by the cooling, whereas it strongly depends on the field-dependent domain-wall motion for the continuous FePt-film. By combining ultrafast X-Ray diffraction and FEM-modeling we show that the concomitant lattice response in both specimen is governed by the varying degrees of in-plane motion for both specimen. We present a versatile two-pulse excitation scheme in which the first laser pulse induces a demagnetization, while the second pulse triggers a strongly magnetization-dependent lattice response in the FePt nanograins.