Temperature-induced coupled–decoupled transition in perpendicular pseudo spin valves

Abstract

The effect of spacer and ferromagnetic layer thickness on temperature-dependent magnetostatic coupling in perpendicular magnetic anisotropy pseudo spin valves (PMA-PSVs) with the structure of [Ni/Co]5/Cu(dCu)/[Ni/Co]n is explored theoretically. We introduce an effective field that controls the domain replication mechanism and coupling in PSVs. The decoupling temperature (Tdecoupling) can be determined by considering the temperature dependence of the effective field and the coercivity of the hard layer of the PSVs. This study reveals that by increasing the spacer layer thickness, the effective field decreases and Tdecoupling has an increasing trend. Furthermore, by increasing the hard ferromagnetic layer thickness, which is accompanied by an increase in the anisotropy of the layer, Tdecoupling again has an increasing trend. The results are comparable to recently reported experimental ones for PMA-PSVs with various spacer thicknesses, dCu, and the number of bilayer repeats, n. As a practical result, this work gives a deep understanding of the magnetostatically driven domain replication mechanism and temperature-induced coupled–decoupled transitions in PMA-PSVs.