학술논문

A Split-Pole-Gapped NFT Write Head Design for Transition Curvature Reduction in Heat-Assisted Magnetic Recording
Document Type
Periodical
Author
Source
IEEE Transactions on Magnetics IEEE Trans. Magn. Magnetics, IEEE Transactions on. 54(11):1-4 Nov, 2018
Subject
Fields, Waves and Electromagnetics
Magnetic heads
Media
Optical surface waves
Gold
Heat-assisted magnetic recording
Adaptive optics
Heat-assisted magnetic recording (HAMR)
near-field transducer (NFT)
recording head
transition curvature
Language
ISSN
0018-9464
1941-0069
Abstract
A write head design consisting of a split pole and a gapped near-field transducer is presented. Through simulation, we found our design can produce a maximum effective cross-track recording field gradient of 300 Oe/nm, and a maximum difference of 3.6 kOe between the center and ±20 nm away in the cross-track direction in the recording media near the magnetic gap (MG). The tradeoff between improved cross-track magnetic gradient and loss of optical efficiency due to parasitic absorption by the pole is studied as a function of the thickness of a low optical-index separator between the MG and the optical gap (OG). The separator is tapered to bring the cross-track field gradient close to the OG near the air bearing surface, while limiting the total amount of interaction of the evanescent optical field with the pole. With this tapered low-index separator, we are able to preserve the recording field cross-track gradient and amplitude, while reducing the parasitic optical absorption in the recording head due to pole proximity.