Magnetostatic coupling in spin valves: Revisiting Néel’s formula

Abstract
We use a numerical, atomistic approach to calculate the magnetostatic coupling in spin valves. In addition to the numerical treatment, the coupling energy is evaluated analytically and it is shown that Néel’s formula is accurate to first order in the ratio of roughness amplitude to grain size. We also generalize the formula so that it can be applied to systems such as Py/Co/Cu/Co/Py spin valves that have complex ferromagnetic layers.