Interlayer exchange coupling in perpendicularly magnetized Pt/Co/Ir/Co/Pt structures

The occurrence of both interlayer exchange coupling and perpendicular magnetic anisotropy is evidenced in Pt/Co/Ir/Co/Pt magnetron sputtered structures. We point out the effect of lattice strains on stabilizing the perpendicular magnetic anisotropy. The surface magnetic anisotropy constant is around 1.76 erg cm−2 and around 1.5 erg cm−2 for the Co layers, depending on their positioning within the stack. We demonstrate a relatively high interlayer exchange constant of −2.5 erg cm−2 at the first antiferromagnetic coupling maximum corresponding to an exchange field larger than 12 kOe. The interlayer exchange coupling shows remarkable annealing endurance being preserved for annealing temperatures up to 400 °C.