Dresden 2006 – scientific programme

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MA: Magnetismus

MA 28: Invited Talks Brune / Moritz

MA 28.2: Invited Talk

Thursday, March 30, 2006, 14:30–15:00, HSZ 03

Discrete media made from pre-patterned wafers: a promising route towards ultra high density magnetic recording — •Jerome Moritz, Mohamed Asbahi, Vincent Baltz, Bernard Rodmacq, Jean-Pierre Nozieres, and Bernard Dieny — SPINTEC, URA 2512 CEA/CNRS, Grenoble, France

Patterned media have been proposed as a route to increase the areal density in magnetic storage devices towards 1 Tbit/in2 because they allow circumventing the super-paramagnetic limit, which is expected to appear in conventional media at densities ~300 GB/in2. Pre-patterned media are prepared by classical lithography or nanoimprinting at the Silicon wafer level, followed by magnetron sputtering of Co/Pt multilayers. A bit binary value (0 or 1) is associated with the orientation of the magnetization carried by each dot. It is also possible to stack several layers with different coercive properties on top of the dots and to obtain 2^N stable states (N being the number of layers). An octet could then be coded on only one dot for instance, which leads to a drastic increase in the information density. The recording performances have been studied by using a quasi-static tester equipped with commercial write/read heads. The pulse width of the write field was varied from 1 s down to 1 nanosecond. The possibility of high data transfer rates was demonstrated. The signal to noise ratio of the readback signal is competitive with classical continuous media especially at small bit length. The improvements in nanoimprint lithography make this approach based on pre-patterned wafers promising for future ultrahigh density hard disk drives.