Magnetization reversal of elliptical Co/Cu/Co pseudo-spin valve dots

We present our recent simulated results on Cr (5 nm)/ Cu (5 nm)/ Co (5 nm)/ Cu (3 nm)/ Co (2 nm) pseudo-spin valve dots. The simulated results agree qualitatively with the experimental results. Three different sizes of elliptical dots, 150nm×105nm, 175nm×70nm, and 200nm×60nm, were simulated. Our simulations show that in these types of dots magnetization reversal occurs by the formation of domain walls: 90° for 175nm×70nm and 360° for 200nm×60nm. No domain wall was observed in the reversal of the 150nm×105nm dots. For such dots, the simulated loops show a small two-step reversal pattern with the thin upper layer partially reversing followed by complete reversal of both layers at higher fields. In the larger dots, a two-step reversal is clearly observed both in the simulation and experiment.