The reversed word field switching threshold for M-R memory elements

An experimental and analytical study was performed on the threshold properties of 1.5×5-μm² and 1.8×18-μm² magnetoresistive memory cells (MR) for rotational switching when a reverse word field (opposed to the edge magnetization) is applied. The results show that the threshold for reverse switching requires larger fields than normal because of the energy associated with the formation of walls at the element edges. In the case of reverse switching (for a stored `one´), the wall energy is sufficient to restore the element to its original state when the word field is removed for the 1.5- and 1.8-μm-wide elements. If the elements are made wide enough, the wall energy is not sufficient to cause return switching. The current analytical model adequately accounts for the normal and reverse switching threshold when demagnetization corrections are taken into account. The model does not adequately account for the return switching threshold as a function of sense current