Kazuyuki Ise

High writing-sensitivity single-pole head with a cusp field coil

A new design for a high writing-sensitivity single-pole head is proposed. The head is driven with regular pancake structure dual coils, which sandwiches the main-pole. The outer parts of both coils are exposed to the air bearing surface. These coils can generate a cusp field with bifilar connection. A high recording sensitivity of this new head has been clarified by the fact that a small magnetomotive force of less than 0.1 AT/sub 0-P/ can saturate a medium with a high-coercivity of 3.5 kOe.

New Shielded Single-Pole Head With Planar Structure

A planar-type single-pole head for perpendicular magnetic recording which is combined with multicharged-surface main-pole structure for a strong head field and with a wraparound shield for steep head field distribution has been newly devised. The head field strength of the new head is less influenced by the thickness of the shield compared with that of the conventional shielded single-pole head whose pole tip is straight. This new head was fabricated using a different technique from the present head

A new single-pole head structure for high writability

A new single-pole-type head with a novel structure has been developed. The head has a set of coil windings located on both sides of the main pole and two return path yokes surrounding the main pole and the coil. This head structure provides high stray field immunity due to a shielding effect of the return yokes. Head, field calculation was performed to design the head in terms of high writability. It was found that the head generates preferable field distribution and the field strength and gradient can be improved by reducing throat height of the main pole and narrowing separation of the main pole and the return yoke, respectively. This was experimentally confirmed with fabricated heads. The 0.2 /spl mu/m-wide head showed a high writing performance.

High Field-Gradient Design of Single-Pole Write-Head With Planar Pole Structure

A planar single-pole head generating a large head field was investigated to improve head field distribution with a steep field gradient. Good writing performance is generally difficult for a narrow track writer. This work presents a novel design of the main pole shape, the three-step-slope, to achieve a high gradient and strong write head field for terabit recording. Furthermore, the medium design was investigated to increase head-to-medium interaction for achieving a high field gradient and narrow field distribution. A soft guard band in the recording layer and a cross-track groove on the SUL surface were effective for improving the field gradient.

High-field gradient cusp field single-pole writing head with front return yoke

The relationship between single-pole head design and recording resolution was investigated in perpendicular recording. It has been found from the computer simulation that it is useful to make a narrow separation between the main pole and the return yoke at the trailing side of the cusp-field single-pole-type (CF-SPT) head. A new head structure with an additive return yoke on the head surface was proposed to realize the aforementioned structure. The new head was fabricated by depositing the soft magnetic thin film onto the air-bearing surface of the CF-SPT head, followed by slitting the film along the main-pole edges by a focused-ion-beam system. As a result, the new head that modified a pole configuration improved D/sub 50/ value about 25 kFCI compared with the original CF-SPT head.

High writability head with robustness against stray field and narrow-track recording properties

A new cusp-field single-pole-type head with a novel structure has been developed. The coil windings of the head are located on both side of the main pole and produce cusped magnetic field to energize the main pole. Dual return-path-yokes are formed in adjacent to the coils. Head field calculations were performed to design the head in terms of high writability. The new head exhibited a small field from the return-path-yoke itself. The writing field amplitude from the main pole was found to increase by reducing the throat height of the main pole without any significant field broadening in cross-track direction. Furthermore, the field gradient could be improved by narrowing the separation between the main pole and the return-path-yoke, resulting in a high linear resolution as confirmed in an experiment. The new head also provided high stray field immunity due to a shielding effect of the dual return-path-yokes.

Cusp field single pole head with high recording resolution

Summary form only given. In perpendicular recording, large head field gradient is very essential to realize a high recording resolution, especially for low noise double layered media with a small M-H loop slope. The structure of cusp field SPT heads was investigated to improve high linear density characteristics.

Writing performances of cusp-field single-pole head

The writing performance of a novel single-pole head, named as CF-SPT head, on double-layer perpendicular media was studied. The CF-SPT head was effectively driven with dual pancake-type coils between which the main-pole was sandwiched. Furthermore, it was found that the head with double return-yoke showed a high stray field robustness and an efficient recording performance when compared with a single return-path-yoke head.

High frequency inductance measurements and performance projections made for cusp-field single pole heads

As the rigid disk drive industry has progressed to higher RPM to improve access times via latency reduction, the need for higher performance write and read channel electronics as well as heads has arisen. It appears that perpendicular recording is becoming a next generation candidate as a result of its advantage over longitudinal recording in the area of thermal stability. It is the ultimate frequency response of the head impedance that we wish to explore in this paper and measurements of the high frequency inductance can be used to provide considerable insight into the potential performance of recording heads. The cusp-field single pole head has several unique features that make it worthy of study. This paper is based upon the experimental procedure of first characterizing the head alone followed by the inclusion of the medium and its underlayer. Finally, frequency response comparisons are made between a commercial longitudinal recording head and several low turn cusp-field heads. The conclusions provide a practical bit rate limit for the cusp-field head based on the modeling results, experimental high frequency inductance data, and spin reversal.

Permeability of microstrip thin films of various materials

Soft magnetic bilayered microstrip films have been studied for various materials such as Ni–Fe–Mo–Cu, Co–Zr–Mo–Ni, Fe–Si–N, and Ni–Fe in terms of their magnetization dynamics. Effects of the strip width and the interlayer thickness on permeability were investigated. An optimum interlayer thickness was found for obtaining the maximum permeability for those films except Fe–Si–N, but the optimum value differs in magnetic film material. A scanning Kerr effect microscope observation reveals that permeability variations with strip width related to changes of the dynamic domain configurations of the strips. All magnetic film materials except Fe–Si–N show a high permeability of more than 1000 at 2 μm strip width at each optimum interlayer thickness. When the film width is reduced to 1 μm, however, the permeability decreases significantly regardless of the interlayer thickness and kinds of the film materials. For such narrow strip film, a higher permeability is obtained for higher anisotropy field. It is concluded...