G11B5/33

Heat-assisted magnetic recording (HAMR) disk drive with disk having multiple continuous magnetic recording layers

A heat-assisted magnetic recording (HAMR) disk drive has a disk with at least two independent data layers (RL1 and RL2), each data layer storing an independent data stream. At a high laser power both RL1 and RL2 are heated to above their respective Curie temperatures and a first data stream is recorded in both RL1 and RL2. At a lower laser power only upper RL2 is heated to above its Curie temperature and a second data stream is recorded only in RL2. The data layers are separated by a nonmagnetic spacer layer (SL) that prevents lower RL1 from being heated to above its Curie temperature at low laser power. The first and second data streams are typically asynchronous. Recorded data is read back from both data streams simultaneously as a composite readback signal. A joint Viterbi detector detects the asynchronous data streams simultaneously from the composite readback signal.

Heat-assisted magnetic recording (HAMR) disk with multiple continuous magnetic recording layers

A heat-assisted magnetic recording (HAMR) disk has multiple independent data layers, each data layer being a continuous non-patterned layer of magnetizable material. Each data layer can store data independent and not related to the data stored in the other data layers. The data layers are separated by a nonmagnetic spacer layer (SL) and each data layer is formed of high-anisotropy (K.sub.u) material so that the coercivities of lower and upper data layers (RL1 and RL2) are greater than the magnetic write field. At a high laser power both RL1 and RL2 are heated to above their respective Curie temperatures and data is recorded in both RL1 and RL2. At low laser power only upper RL2 is heated to above its Curie temperature and data is recorded only in RL2. The SL prevents lower RL1 from being heated to above its Curie temperature at low laser power.

Two-dimensional magnetic recording device with center shield stabilized by recessed AFM layer

A two-dimensional magnetic recording (TDMR) read head with an antiferromagnetic (AFM) layer recessed behind a center shield. The TDMR read head comprises a first read sensor and a center shield over the first read sensor, wherein the center shield has a first thickness at an air-bearing surface (ABS) and a second thickness at a back surface, the first thickness being greater than the second thickness. A ferromagnetic layer is disposed over a portion of the center shield, wherein the ferromagnetic layer is recessed from the ABS. The TDMR read head also includes an antiferromagnetic layer over the ferromagnetic layer and a second read sensor over the antiferromagnetic layer. By recessing the AFM layer away from the ABS, the down-track spacing between read sensors is reduced, thereby improving TDMR read head performance.

CoFe/Ni multilayer film with perpendicular anisotropy for microwave assisted magnetic recording

A spin transfer oscillator (STO) with a seed/FGL/spacer/SIL/capping configuration is disclosed with a composite seed layer made of Ta and a metal layer having a fcc(111) or hcp(001) texture to enhance perpendicular magnetic anisotropy (PMA) in an overlying (A1/A2).sub.YFeCo laminated field generation layer (FGL). The spin injection layer (SIL) may be laminated with a (A1/A2).sub.XFeCo configuration. The FeCo layer in the SIL is exchanged coupled with the (A1/A2).sub.X laminate (x is 5 to 50) to improve robustness. The (A1/A2).sub.Y laminate (y=5 to 30) in the FGL may be exchange coupled with a high Bs layer to enable easier oscillations. A1 may be one of Co, CoFe, or CoFeR where R is a metal, and A2 is one of Ni, NiCo, or NiFe. The STO is typically formed between a main pole and trailing shield in a write head.

CoFe/Ni multilayer film with perpendicular anisotropy for microwave assisted magnetic recording

A spin transfer oscillator (STO) with a seed/FGL/spacer/SIL/capping configuration is disclosed with a composite seed layer made of Ta and a metal layer having a fcc(111) or hcp(001) texture to enhance perpendicular magnetic anisotropy (PMA) in an overlying (A1/A2).sub.YFeCo laminated field generation layer (FGL). The spin injection layer (SIL) may be laminated with a (A1/A2).sub.XFeCo configuration. The FeCo layer in the SIL is exchanged coupled with the (A1/A2).sub.X laminate (x is 5 to 50) to improve robustness. The (A1/A2).sub.Y laminate (y=5 to 30) in the FGL may be exchange coupled with a high Bs layer to enable easier oscillations. A1 may be one of Co, CoFe, or CoFeR where R is a metal, and A2 is one of Ni, NiCo, or NiFe. The STO is typically formed between a main pole and trailing shield in a write head.

Magnetic recording head writer having an auxiliary magnetomotive force coil

Described are magnetic recording heads that include auxiliary current wires that drive the write pole tip, augmenting the main coils that provide magnetomotive force to the write pole. The auxiliary wires are provided in close proximity to the write pole tip near the media-facing surface of the recording head, and are preferably in closer proximity to the write pole tip than are the main coils. In certain writer designs that include one or more heat sink structures positioned near or around the write pole tip, such as may be found in heat-assisted magnetic recording writer constructions, the auxiliary wire(s) may be accommodated near or around the heat sink structures, or the heat sink structures themselves can serve as the auxiliary wires.