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

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 thiswork, we focus on the impact of the FM/NMinterface 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 L1(0)-FePt alloy interlayer. Subsequently, we establish that a Fe/L1(0)-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.

Automated summary

Recent developments in nanomagnetism and spintronics have enabled the use of ultrafast spin physics for terahertz emission. This paper focuses on the impact of the interface between ferromagnetic (FM) and non-magnetic (NM) thin film heterostructures on terahertz emission, specifically by investigating the modification of the Fe/Pt interface using an ordered L1(0)-FePt alloy interlayer. It is found that a Fe/L1(0)-FePt (2 nm)/ Pt configuration shows significantly higher terahertz emission amplitude compared to a Fe/Pt bilayer structure, depending on the extent of alloying on either side of the interface. This trilayer structure opens up new possibilities for material choices in the next generation of spintronic terahertz emitters.