Thermal Stability of Ni-Fe/Co/Au/Co GMR Pseudo-Spin-Valves

Pseudo-spin-valves (PSV) structures, Ni₈₃Fe₁₇-3 nm / Co-2.5 nm / Au-t _Au / Co-2.5 nm, with 2.4t _Au3.2 nm were deposited by UHV magnetron sputtering. The weak ferromagnetic coupling J2×10^-6 J/m² between Ni-Fe/Co and Co layers and GMR effect 3% was found at RT. The GMR amplitude decreases monotonically from 5% at -100°C to 1% at 200°C. However, the slope of R(H) curve, i.e., GMR field sensitivity, is equal to about 1.5%/Oe and remains almost constant in the entire investigated temperature range. Additionally, our PSV display a good thermal stability, with no significant changes of magnetic and transport properties after annealing up to 250°C.