Patterned perpendicular magnetic recording medium with data islands having a flux channeling layer below the recording layer

摘要

A patterned perpendicular magnetic recording medium, such as a disk for use in hard disk drives, has a flux channeling layer (FCL) located below the recording layer (RL) in each of the discrete data islands. The disk includes a substrate, a soft underlayer (SUL) of soft magnetically permeable material on the substrate, and a nonmagnetic exchange break layer (EBL) on the SUL. A nonmagnetic separation layer (SL) is located between the FCL and the RL in the islands. The FCL has an anisotropy field substantially lower than the anisotropy field of the RL, and a magnetization equal to or higher than the magnetization of the RL. The FCL is saturated at a much lower field than the RL and thus channels the magnetic flux from the write head through the island positions. The dipolar fields from the RL above the FCL polarize the magnetization of the FCL parallel to the magnetization direction of the RL in the absence of an external field, to thereby enhance the readback signal.

主权项

1. A patterned perpendicular magnetic recording medium comprising:
a substrate having a substantially planar surface;a soft underlayer (SUL) of soft magnetically permeable material on the substrate surface and having a planar surface;
an exchange break layer (EBL) of nonmagnetic material comprising a base layer of EBL material covering the entire planar surface of the SUL and a plurality of pillars of EBL material extending from the base layer of EBL material; and a plurality of discrete islands, each island located on a pillar of EBL material and comprising a flux channeling layer (FCL) on the EBL material of the pillar and prevented from exchange coupling with the SUL by the EBL material, a perpendicular magnetic recording layer (RL), and a nonmagnetic separation layer (SL) on the FCL between the FCL and the RL for preventing magnetic exchange coupling between the FCL and the RL, the FCL formed of a soft magnetic material having an anisotropy field lower than the anisotropy field of the RL and a magnetization higher than the magnetization of the material of the RL, the RL and FCL having parallel magnetizations perpendicular to the substrate surface.