Perpendicular magnetic anisotropy in nanocomposite Nd-Fe-B/FeCo bilayer films

Nd-Fe-B/FeCo bilayer films with Mo underlayers and overlayers have been investigated. All the samples have perpendicular anisotropy and the magnetization is found to increase with increasing FeCo layer thickness (dFeCo) and the coercivity decreases with increasing dFeCo. The maximum energy-product is 20 MGOe for dFeCo = 5 nm. The enhancement of the remanence and energy products in the bilayer films is attributed to the exchange coupling between the magnetically soft and hard phases.