Shielded planar write head

Effectiveness of the magnetostatic shielding by the cylindrical shells

“…In the literature on the theory of the shielding functions calculation, the problem of the shielding of the homogeneous magnetic fields for the cases of simple geometric shapes -infinite plane, infinite cylindrical and spherical shields is the most successful and thoroughly solved [4,14]. For these cases the basic essence of the physical phenomena just enough reveals and the basic formulas are obtained connecting the parameters of the electromagnetic radiation (EMR) and the shields with the shielding effectiveness.…”

Shingled Writer Design for 10 ${\rm Tb/in}^{2}$ Patterned Media Recording

“…The targeted areal density of this work is 10 , which corresponds to a cell center-to-center pitch of 8 nm. Compared with the media parameters required for achieving 10 patterned media recording in [3], the corresponding patterned Manuscript media parameters reported in this work are much more feasible: a cell-to-cell gap being increased from 2 to 3 nm, intermediate layer thickness being increased from 0 to 2 nm whilst the magnetic film thickness remains the same (7 nm), magnetic spacing between magnetic head and media being increased from 1.5 to 3 nm, media saturation magnetization being decreased from 2000 emu/cc to a much more feasible value of 1300 emu/cc.…”

“…Writing head with wrap-around shield is widely used in shingled writing head designs [8]- [10]. The parameters of the shingled writing head used in this work are shown in Fig.…”

“…The total elements number is around . The material characteristics are as follows [8]- [10]: the saturation magnetization of the entire writer and SUL are 1910 and 1600 emu/cc, respectively; anisotropy constant of the writer material and SUL are both set to with in-plane direction; exchange constant for all materials are set to . Since only the static field distribution is needed, Gilbert damping factor of 0.5 is chosen for quick calculations.…”

Future hard disk drive systems

“…For the writer, every effort will be made to channel as much flux as possible to the pole-tip [16,20]. Control of 'mag.-noise' will continue to be a focus, especially for CPP GMR heads where spin-torque-induced instability can be an issue.…”