Bit-Patterned Magnetic Recording

The proposal of exchange-coupled composite (ECC) media datesback to 2005 [1, 2], when two different papers independentlyproposed to exploit the old concept of exchange-spring magnet to improve the writability of perpendicular recording media [3]. Thesepapers suggested adding a soft magnetic layer to hard magneticmedia, thus exploiting the hard-to-soft exchange coupling to reducethe media writing field and keep high thermal stability.