At the Materials Research Society in Boston, Bruce Terris from the Hitachi San Jose (Calif.) Research Center has described a process for creating cobalt-palladium nanoscale islands on silicon dioxide that could carry magnetic media densities into the terabit/square-inch realm. This process was developed in a joint project with researchers at IBM Almaden Research Center
For current approaches, theoretical predictions point to a physical limit somewhere around 100 Gbits/inch2. By using the nano-island technique some of the factors leading to that limit are avoided. It allows for vertically polarized magnetic domains to be created, reducing the crosstalk between neighboring bits. The theoretical limit is also overcome by regular nanopatterning isolating individual magnetic domains on islands.
The process used nanoimprint lithography to create an etch mask on a silicon dioxide substrate. Then multilayers of cobalt and palladium were sputtered onto the SiO2 islands. As the resulting domains were isolated rather than in a continuous film, they showed higher coercivity and were more resistant to thermal effects.