  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.
