40 results about "Perpendicular media" patented technology

A perpendicular writer of the present invention comprises a main pole connected to two return poles and further includes one or more shorting shields thereby reducing erasure field on double layer perpendicular media. The perpendicular writer may include side shorting shields connecting the first and second return poles thereby modifying the crosstrack field gradient. Additionally, the perpendicular writer may include a top shorting shield modifying the downtrack gradient and may additionally include a bottom shorting shield for further reduction of erasure fields. The distance between the main pole and the shorting shields may be modified to customize the write field gradient.

A perpendicular magnetic recording data storage system combines a perpendicular medium that has a thin low-magnetic-permeability or “soft” underlayer (SUL) with a recording head that has a trailing shield (TS) with a thick throat height, i.e., a thickness in a direction orthogonal to the recording layer of the medium. The SUL is thin enough and has a low enough magnetic permeability to become saturated in a region beneath the trailing gap of the head during writing, but the throat height of the TS is thick enough to prevent the TS from becoming magnetically saturated during writing. The magnetic saturation of the SUL during writing changes the magnetic reluctance such that more of the magnetic flux going through the SUL changes direction (“field undershoot”) and goes to the TS. If the permeability of the SUL is so low (e.g., close to unity) that the SUL does not magnetically saturate, field undershoot may still occur because the reluctance from the SUL to the TS is still smaller than the reluctance from the SUL to the return pole (RP). Field undershoot enables a high write field gradient, which results in narrower magnetic transitions.

Carbon or boron is added into the CoCr layers of a multiplayer perpendicular magnetic media structure to reduce media noise. The perpendicular magnetic media structure has sharp interfaces between Co-alloy layers and Pd or Pt layers and significantly reduced exchange coupling. In accordance with one embodiment of the invention, the perpendicular magnetic media structure with carbon or boron additives is 700 Å FeCo30.8B12 / 20 Å TaOx / 700 Å FeCo30.8B12 / 20 Å TaOx / 700 Å FeCo30.8B12 / 20 Å TaOx / 158 Å FeCo30.8B12 / 17 Å Ta / 49 Å ITO / 33 Å CoCr37Ru10 / 2.5 Å COy / 2.5 Å C / [(CoCr9)C6.8 / Pd]19 / 50 Å CHN. [(CoCr9)C6.8 / Pd]19 means 19 layers of the bi-layer stack (CoCr9)C6.8 / Pd. TaOx stands for surface-oxidized Ta and COy stands for C oxides. ITO stands for Indium Tin Oxide and consists of In2O3 and Sn2O5 at 80 and 20 molecular percent respectively. CHN refers to hydrogenated and nitrogenated carbon.

A recording medium having a substrate, a first soft magnetic underlayer, a second soft magnetic underlayer and a perpendicular magnetic recording layer without a spacer layer between the first and second soft magnetic underlayers is disclosed.

A method for estimating the average intergranular exchange field using measurements of major and minor hysteresis loops. The method also facilitates deshearing hysteresis loops for analysis purposes in perpendicular media. This estimation technique is especially important for modern perpendicular media because exchange plays a critical role and process control can be difficult.