Exchange spring media (also exchange coupled composite media or ECC[1]) is a magnetic storage technology for hard disk drives that allows to increase the storage density in magnetic recording.
The idea, proposed in 2004 by Suess et al.,[2] is that the recording media consists of exchange coupled soft and hard magnetic layers.
Exchange spring media allows a good writability due to the write-assist nature of the soft layer.
Small grain sizes are required for high density recording.
[3] Besides the improved writeability, another advantage of exchange spring media is, that the switching field distribution of the grains, which has to be as small as possible to allow for high storage densities, can be decreased.