THz emission from Fe/Pt spintronic emitters with L10-FePt alloyed interface

Laura Scheuer; Moritz Ruhwedel; Dimitrios Karfaridis; Isaak G Vasileiadis; Dominik Sokoluk; Garik Torosyan; George Vourlias; George P Dimitrakopoulos; Marco Rahm; Burkard Hillebrands; Thomas Kehagias; René Beigang; Evangelos Th Papaioannou

doi:10.1016/j.isci.2022.104319

THz emission from Fe/Pt spintronic emitters with L1₀-FePt alloyed interface

iScience. 2022 Apr 29;25(5):104319. doi: 10.1016/j.isci.2022.104319. eCollection 2022 May 20.

Affiliations

¹ Fachbereich Physik and Landesforschungszentrum OPTIMAS, Technische Universität Kaiserslautern, Kaiserslautern 67663, Germany.
² Department of Physics, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece.
³ Fachbereich Elektro-Informationstechnik and Landesforschungszentrum OPTIMAS, Technische Universität Kaiserslautern, Kaiserslautern 67663, Germany.
⁴ Photonic Center Kaiserslautern, Kaiserslautern 67663, Germany.
⁵ Fachbereich Physik, Technische Universität Kaiserslautern, Kaiserslautern 67663, Germany.
⁶ Institut für Physik, Martin-Luther Universität Halle Wittenberg, Von-Danckelmann-Platz 3, 06120 Halle, Germany.

Abstract

Recent developments in nanomagnetism and spintronics have enabled the use of ultrafast spin physics for terahertz (THz) emission. Spintronic THz emitters, consisting of ferromagnetic (FM)/non-magnetic (NM) thin film heterostructures, have demonstrated impressive properties for the use in THz spectroscopy and have great potential in scientific and industrial applications. In this work, we focus on the impact of the FM/NM interface on the THz emission by investigating Fe/Pt bilayers with engineered interfaces. In particular, we intentionally modify the Fe/Pt interface by inserting an ordered L1₀-FePt alloy interlayer. Subsequently, we establish that a Fe/L1₀-FePt (2 nm)/Pt configuration is significantly superior to a Fe/Pt bilayer structure, regarding THz emission amplitude. The latter depends on the extent of alloying on either side of the interface. The unique trilayer structure opens new perspectives in terms of material choices for the next generation of spintronic THz emitters.

Keywords: Physics; Radiation physics; Radiation transport.