A study on thin-film-media noise by magnetic domain observation

Author

Aoi, H. ; Tsuchiya, R. ; Shiroishi, Y. ; Matsuyama, H.

Author_Institution

Hitachi Ltd., Tokyo, Japan

Volume

24

Issue

6

fYear

1988

fDate

11/1/1988 12:00:00 AM

Firstpage

2715

Lastpage

2717

Abstract

Magnetic domain structures of signal-recorded and reverse-DC-erased thin-metal-film media with different signal-recorded noise characteristics have been observed by a spin-polarized scanning electron microscope to determine the noise-generating mechanism. In noisy media, magnetic domains around 10-μm wide grow at 38 KFCI, and recorded transitions are observed inside them. At the maximum reverse-DC-erase noise condition, which corresponds to the DC demagnetized condition, magnetic domains from 2- to 5-μm wide are observed. In low-noise media, no large, distinct domains are seen for either condition. The squareness (M_r/M_s) of noisy media is 10% higher and the switching field distribution (Δh/H_r) is 40% lower than those of low-noise media. The results indicate that large signal-recorded noise is generated from large irregular magnetic domains that grow through strong exchange coupling between crystallites

Keywords

magnetic domains; magnetic thin films; metallic thin films; noise; scanning electron microscope examination of materials; SEM; domain structures; exchange coupling; low-noise media; magnetic domain observation; noise characteristics; noise-generating mechanism; recorded transitions; reverse-DC-erased media; scanning electron microscope; signal recorded media; signal-recorded noise; spin-polarized; switching field distribution; thin-film-media noise; Disk recording; Gaussian noise; Magnetic domains; Magnetic field measurement; Magnetic heads; Magnetic noise; Magnetic recording; Neodymium; Noise measurement; Scanning electron microscopy;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/20.92222

Filename

92222