Cusp-Field Single-Pole-Type (CF-SPT) Head for Perpendicular Recording

  • Kiyoshi Yamakawa
Part of the Nanostructure Science and Technology book series (NST)


Maintaining the thermal stability of small magnetic grains is important for perpendicular magnetic recording; for achieving higher recording densities, it is inperative to continue to increase the strength and sharpness of the magnetic recording field of single-pole-type (SPT) heads because the anisotropy energy of the recording media becomes large, thereby threatening the thermal stability. Development of soft magnetic pole material with a high saturation magnetic flux density, B s, is the first requirement. Furthermore, improvement of the head structure is important because little room is left for the B s increasing to its practical limit of 2.45 T.

The first single-pole head was developed as an auxiliary-pole-driven-type head [1]. This head underscored the importance of the head-energizing method for realizing a strong and sharp recording field in which the coil created the strongest field at the top in the main pole located at the air-bearing surface (ABS). This concept was inherited by the thin film SPT head [2] depicted in Fig. 8.1a. In the head, the coil of the helical structure is wound closely around the main pole throat to excite the pole tip directly with the strongest coil field. As depicted in Fig. 8.1b, field calculations reveal that the highest head field was obtained when the coil recession height, h, from the ABS was zero.


Seed Layer Main Pole Stray Field Coil Field Head Field 
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Copyright information

© Springer Science+Business Media, LLC 2010

Authors and Affiliations

  1. 1.Akita Research Institute Of Advanced Technology (AIT)ArayaJapan

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