Critical-field curves for switching toggle mode magnetoresistance random access memory devices (invited)

The magnetization behavior of generalized synthetic antiferromagnet (SAF) is investigated by analytic/numeric method, applying Stoner–Wohlfarth model to each layer. Critical conditions for toggle-mode switching are given using the critical-field curves obtained from the field trajectories giving a constant value to the average angle of the magnetizations of the two layers or to the angle between the two, leaving the other variable. The critical fields for the toggle operation are found to be expressed by analytical formulas including only controllable element parameters, facilitating the parameter optimization for the memory element. The results obtained for the generalized SAF are useful in determining the tolerance for the parameter imbalance. Half-select disturb effect is still one of the important issues to be taken into account in designing the memory element.