Patterned media for future magnetic data storage

One strategy to delay the onset of superparamagnetism and achieve magnetic storage densities approaching 1 Tb/in.2 is the use of lithographically patterned magnetic media. While one of the main advantages enjoyed by magnetic recording is low cost due to use of featureless media, there are several advantages that may be realized by patterning the medium in a hard disk drive. The commercial success of patterned media will of course depend on the relative costs and gains. In particular, there are three main types of disk patterning proposed, each requiring a different length scale of patterned feature. Patterning of servo marks for maintaining the head position on-track, the fabrication of discrete tracks, and the fabrication of discrete bits have all been proposed and will be discussed. For discrete bit recording single domain magnetic islands are required, and one approach to fabricating these, by depositing magnetic films onto prepatterned substrates, is described. The switching characteristics of the islands as compared to those of the full film, along with initial recording results are presented.

[1]  G. Hu,et al.  Angular dependence of the switching field in patterned magnetic elements , 2005 .

[2]  Margaret Evans Best,et al.  Magnetic characterization and recording properties of patterned Co/sub 70/Cr/sub 18/Pt/sub 12/ perpendicular media , 2002 .

[3]  T. Albrecht,et al.  Magnetic lithography using flexible magnetic masks: applications to servowriting , 2003, Digest of INTERMAG 2003. International Magnetics Conference (Cat. No.03CH37401).

[4]  H. Neal Bertram,et al.  Theory of Magnetic Recording , 1994 .

[5]  Margaret Evans Best,et al.  Writing and reading perpendicular magnetic recording media patterned by a focused ion beam , 2001 .

[6]  J. Chen,et al.  Demonstration and characterization of 130 Gb/in2 magnetic recording systems , 2003 .

[7]  C. Rettner,et al.  Effect of ion beam patterning on the write and read performance of perpendicular granular recording media , 2001 .

[8]  C. Rettner,et al.  Rotation and wall propagation in multidomain Co/Pd islands , 2005, IEEE Transactions on Magnetics.

[9]  G.F. Hughes.  Read channels for pre-patterned media, with trench playback , 2003, Digest of INTERMAG 2003. International Magnetics Conference (Cat. No.03CH37401).

[10]  Margaret Evans Best,et al.  Recording performance of high-density patterned perpendicular magnetic media , 2002 .

[11]  C. Rettner,et al.  Magnetization reversal in Co/Pd nanostructures and films , 2005 .

[12]  C. Ross.  Patterned Magnetic Recording Media , 2001 .

[13]  T. Albrecht,et al.  Magnetic lithography using a flexible master: A method for instantaneous magnetic recording on media surfaces with flatness imperfections , 2003 .

[14]  Eric E. Fullerton,et al.  Magnetic recording: advancing into the future , 2002 .

[15]  B. Diény,et al.  Writing and reading bits on pre-patterned media , 2004 .

[16]  Bruce D. Terris,et al.  Writing of high-density patterned perpendicular media with a conventional longitudinal recording head , 2002 .

[17]  Margaret Evans Best,et al.  Patterning of granular magnetic media with a focused ion beam to produce single-domain islands at >140 Gbit/in/sup 2/ , 2001 .

[18]  Margaret Evans Best,et al.  Nanoscale patterning of magnetic islands by imprint lithography using a flexible mold , 2002 .

[19]  D. Treves,et al.  Design of a manufacturable discrete track recording medium , 2005, IEEE Transactions on Magnetics.

[20]  Bernard Rodmacq,et al.  Patterned media made from pre-etched wafers: a promising route toward ultrahigh-density magnetic recording , 2002 .

[21]  A. Moser,et al.  Thermal effect limits in ultrahigh-density magnetic recording , 1999 .

[22]  A. Moser,et al.  Thermal Effects in High-Density Recording Media , 2001 .

[23]  T. Thomson,et al.  Angle dependent magnetization reversal of thin film magnetic recording media , 2003 .

[24]  Margaret Evans Best,et al.  Patterned perpendicular and longitudinal media: a magnetic recording study , 2003 .

[25]  M. Sharrock,et al.  Kinetic effects in coercivity measurements , 1981 .

[26]  C. Rettner,et al.  Magnetic and recording properties of Co/Pd islands on prepatterned substrates , 2004 .

[27]  J. Lodder.  Methods for preparing patterned media for high-density recording , 2004 .