L10 Fe-Pd Synthetic Antiferromagnet through an fcc Ru Spacer Utilized for Perpendicular Magnetic Tunnel Junctions

TL;DR

This paper demonstrates a novel L10 FePd/Ru/FePd synthetic antiferromagnetic structure with large perpendicular magnetic anisotropy and strong antiferromagnetic coupling, integrated into magnetic tunnel junctions for advanced spintronic devices.

Contribution

It introduces a new bulk perpendicular synthetic antiferromagnetic structure using an fcc Ru spacer, enhancing magnetic properties for spintronic applications.

Findings

Large bulk perpendicular magnetic anisotropy (~10.2 Merg/cc)

Strong antiferromagnetic coupling (~2.60 erg/cm2)

TMR ratios up to ~25% at room temperature

Abstract

Magnetic materials that possess large bulk perpendicular magnetic anisotropy (PMA) are essential for the development of magnetic tunnel junctions (MTJs) used in future spintronic memory and logic devices. The addition of an antiferromagnetic layer to these MTJs was recently predicted to facilitate ultra-fast magnetization switching. Here, we report a demonstration of a bulk perpendicular synthetic antiferromagnetic (P-SAFM) structure comprised of a (001) textured FePd/Ru/FePd trilayer with a face-centered-cubic (fcc) phase Ru spacer. The L10 FePd P-SAFM structure shows a large bulk PMA (~10.2 Merg/cc) and strong antiferromagnetic coupling (~2.60 erg/cm2). Full perpendicular magnetic tunnel junctions (P-MTJs) with a L10 FePd P-SAFM layer are then fabricated. Tunneling magnetoresistance ratios of up to ~25% (~60%) are observed at room temperature (5K) after post-annealing at 350 C. Exhibiting high thermal stabilities and large Ku, the bulk P-MTJs with an L10 FePd P-SAFM layer could pave a way for next-generation ultrahigh-density and ultra-low-energy spintronic applications.