Bit-Patterned Media for Magnetic Hard Drives

There are of course some problems associated with the use of block copolymers for bit-patterned media. The first lies with the traditionally used block copolymer for most studies to date, PS-fc-PMMA. The relatively weak segregation strength of PS-( -PMMA (x = 0.06) (Russell etfll., 1990) means that an Lq of 20nm (Mn 30000g/mol) is the smallest critical dimension possible before the polymer will fail the condition 10.5, meaning the polymer 

There are also compatibility issues between the lattice geometries of block copolymers and the magnetic arrays that are typically used for bit-patterned media. Considerable amounts of money in the semiconductor industry have been spent on circuit design software and fabrication 

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