Magnetization reversal of giant perpendicular magnetic anisotropy at the magnetic-phase transition in FeRh films on MgO

TL;DR

This paper demonstrates that substituting Ru and Ir in FeRh films on MgO significantly enhances perpendicular magnetic anisotropy, which undergoes a transition at the magnetic phase change, offering potential for advanced spintronic memory devices.

Contribution

It reveals that Ru and Ir substitutions induce large PMA in FeRh films and links this to the magnetic-phase transition, advancing antiferromagnetic spintronics.

Findings

Substitutions of Ru and Ir increase PMA up to 20 erg/cm2.

Magnetization switches from perpendicular to in-plane at phase transition.

Large, switchable PMA linked to magnetic-phase transition in FeRh.

Abstract

Phenomena originated from spin-orbit interaction, such as magnetic anisotropy (MA), Rashba-type interactions, or topological insulators, have drawn huge attention for its intriguing physics. In particular, the search for a novel antiferromagnetic material, with potentially large perpendicular MA (PMA), has been becoming very intensive for next-generation high density memory applications. Here, we propose that substitutions of transition metals Ru and Ir, neighboring and same group elements in the periodic table, for the Rh site in the vicinity of surface can induce a substantially large PMA, up to an order of magnitude of 20 erg/cm2, in FeRh films on MgO. The main driving mechanism for this huge PMA is the interplay between the dxy and dx2-y2 states of strong spin-orbit 4d and 5d orbitals. Further investigations demonstrate that magnetization direction of PMA undergoes a transition into an in-plane magnetization at the antiferromagnetic-to-ferromagnetic phase transition, which provides a viable route for achieving large and switchable PMA associated with the magnetic-phase transition in antiferromagnetic spintronics.