Robust Zero-Field Skyrmion Formation in FeGe Epitaxial Thin Films

TL;DR

This paper demonstrates the growth of high-quality FeGe epitaxial thin films that host dense skyrmions at room temperature and zero magnetic field, advancing low-energy spintronic applications.

Contribution

It reports the first stable, phase-pure FeGe thin films on Si(111) with robust skyrmion formation at zero magnetic field and across a wide temperature range.

Findings

High crystalline quality of FeGe films confirmed by x-ray diffraction and TEM.

Strong topological Hall effect observed indicating dense skyrmions.

Skyrmions stabilized at zero magnetic field from 5 to 275 K.

Abstract

B20 phase magnetic materials, such as FeGe, have been of significant interests in recent years because they enable magnetic skyrmions, which can potentially lead to low energy cost spintronic applications. One major effort in this emerging field is the stabilization of skyrmions at room temperature and zero external magnetic field. We report the growth of phase-pure FeGe epitaxial thin films on Si(111) substrates by ultrahigh vacuum off-axis sputtering. The high crystalline quality of the FeGe films was confirmed by x-ray diffraction and scanning transmission electron microscopy. Hall effect measurements reveal strong topological Hall effect after subtracting out the ordinary and anomalous Hall effects, demonstrating the formation of high density skyrmions in FeGe films between 5 and 275 K. In particular, substantial topological Hall effect was observed at zero magnetic field, showing a robust skyrmion phase without the need of an external magnetic field.