Work

Structural, Magnetic and THz Emission Properties of Ultrathin Fe/L10-FePt/Pt Heterostructures

Year: 2025

Type: article

Abstract: Recent achievements in ultrafast spin physics have enabled the use of heterostructures composed of ferromagnetic (FM)/non-magnetic (NM) thin layers for terahertz (THz) generation. The mechanism of THz emission from FM/NM multilayers has been typically ascribed to the inverse spin Hall effect (ISHE). In this work, we probe the mechanism of the ISHE by inserting a second ferromagnetic layer in the form of an alloy between the FM/NM system. In particular, by utilizing the co-sputtering technique, we fabricate Fe/L10-FePt/Pt ultra-thin heterostructures. We successfully grow the tetragonal phase of FePt (L10-phase) as revealed by X-ray diffraction and reflection techniques. We show the strong magnetic coupling between Fe and L10-FePt using magneto-optical and Superconducting Quantum Interference Device (SQUID) magnetometry. Subsequently, by utilizing THz time domain spectroscopy technique, we record the THz emission and thus we the reveal the efficiency of spin-to-charge conversion in Fe/L10-FePt/Pt. We establish that Fe/L10-FePt/Pt configuration is significantly superior to the Fe/Pt bilayer structure, regarding THz emission amplitude. The unique trilayer structure opens new perspectives in terms of material choices for the future spintronic THz sources.

Source: Nanomaterials

DOI: 10.3390/nano15141099

Authors: Claudiu Locovei, Garik Torosyan, Evangelos Th. Papaioannou, Alina D. Crisan, Rene Beigang, Ovidiu Crisan

Institutions: National Institute of Materials Physics, University of Kaiserslautern, Rheinland-Pfälzische Technische Universität Kaiserslautern-Landau, Aristotle University of Thessaloniki

Language: English

Topic: Magnetic properties of thin films

Subfield: Atomic and Molecular Physics, and Optics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $2,896

Funder: Technische Universität Kaiserslautern