A magnetic disk includes a substrate, a soft magnetic underlayer disposed over the substrate, and a media layer disposed over the underlayer. The underlayer includes a plurality of magnetic layers each containing FeCoN having an atomic concentration of iron that is greater than an atomic concentration of cobalt, and has an atomic concentration of nitrogen that is less than the atomic concentration of cobalt. The atomic concentration of nitrogen is less than eight percent. The underlayer includes a plurality of nonmagnetic layers that are interleaved with the magnetic layers. Each of the nonmagnetic layers has a thickness that is less than one-tenth that of an adjoining layer of the magnetic layers. The media layer contains a magnetically hard material having an easy axis of magnetization oriented substantially perpendicular to both the media layer and the underlayer.