Figure 4
Comparison of Δ from chip data with calculated values. (a) Symbols show normalized values of Δ measured on integrated STT-MRAM chips for two different films stacks (S7 and S8) and three device sizes (chip 8, chip 9, and chip 5) with diameters ranging between 65 and 100 nm. Lines show extrapolations from film data ΔMS (solid line) and ΔDW (dashed line). (b) Experimental data for 100 nm diameter devices from film stack S7 (
) are compared with extrapolations for domain-wall mediated reversal calculated for bulk Fe and CoFe exchange stiffness (dotted and dashed lines, respectively), or by adjusting the exchange stiffness to fit the data (solid line).
