Near field transducers having magnetic inlays for improved heat-assisted magnetic recording
Described are heat-assisted magnetic recording heads that include near-field transducers having a magnetic inlay incorporated into the emitter disk, for example to improve write field properties such as the write field angle (decrease) and/or write field strength (increase), and which can contribute to increased areal density capability. Aspects involve applying an inlay of a magnetic material to the emitter disk of a near-field transducer. The inlay may optionally extend into the sunken disk of the near-field transducer. The inlay thickness, length, shape, and recess from the media-facing surface may be selected or adjusted to achieve desired magnetic, optical, and/or thermal characteristics.
1 . A recording head for heat-assisted magnetic recording, the recording head including a writer that comprises:
a write pole configured to produce a magnetic field for writing data on magnetic media adjacent to a media-facing surface of the recording head, the write pole extending to the media-facing surface;
a near field transducer disposed proximate to the write pole, the near field transducer comprising an emitter disk disposed between a middle disk and a sunken disk, a peg attached to the emitter disk at a peg base and extending toward the media-facing surface, and a waveguide configured to deliver electromagnetic radiation to the sunken disk for coupling into the emitter disk; and
an inlay of magnetic material incorporated into the emitter disk.
2 . The recording head of claim 1 , wherein the inlay has a thickness that extends only through a portion of the emitter disk.
3 . The recording head of claim 1 , wherein the inlay has a thickness that extends through an entire thickness of the emitter disk and into a portion of the sunken disk.
4 . The recording head of claim 3 , further comprising a diffusion barrier disposed between the inlay and the sunken disk.
5 . The recording head of claim 1 , wherein the emitter disk and the inlay have lengths that extend in a direction perpendicular to the media-facing surface, and wherein the length of the inlay is substantially the same as the length of the emitter disk.
6 . The recording head of claim 1 , wherein the emitter disk and the inlay have lengths that extend in a direction perpendicular to the media-facing surface, and wherein the length of the inlay is smaller than the length of the emitter disk.
7 . The recording head of claim 1 , wherein the inlay extends to the peg base.
8 . The recording head of claim 1 , wherein the inlay is recessed from the peg base.
9 . The recording head of claim 1 , wherein the inlay has a different shape from that of the emitter disk.
10 . The recording head of claim 1 , wherein the inlay is composed of NiFe, FeCo, or FeCoX where X is C, Cr, Cu, Ir, Ni, Mo, or V.
11 . The recording head of claim 1 , wherein the inlay has a magnetic moment that is about 1.6 T to about 2.4 T.
12 . The recording head of claim 1 , wherein the inlay has a thickness of about 5 nm to about 85 nm.
13 . The recording head of claim 1 , wherein the inlay is recessed from the media-facing surface by about 15 nm to about 100 nm.
14 . The recording head of claim 1 , wherein the emitter disk forms a shell around the inlay.
15 . The recording head of claim 1 , wherein the presence of the inlay decreases the magnetic field angle during writing relative to a conventional recording head without the inlay.
16 . The recording head of claim 1 , wherein the presence of the inlay increases the magnetic field strength during writing relative to a conventional recording head without the inlay.
17 . The recording head of claim 1 , wherein at least one of the heat sink and the middle disk includes magnetic material.
18 . The recording head of claim 1 , wherein the middle disk and the inlay are recessed from the media-facing surface by the same amount.
19 . The recording head of claim 1 , further comprising a peg coupler disposed adjacent to the write pole at the media-facing surface.
20 . A hard disk drive incorporating the recording head of claim 1 .