Magnetization fluctuations in uniformly magnetized thin-film recording media

Author

Silva, T.J. ; Bertram, H. Neal

Author_Institution

California Univ., San Diego, La Jolla, CA, USA

Volume

26

Issue

6

fYear

1990

fDate

11/1/1990 12:00:00 AM

Firstpage

3129

Lastpage

3139

Abstract

The noise power spectrum of uniformly magnetized media is measured. The measured spectra are corrected for playback effects (gap loss, spacing loss, head differentiation, and amplifier gain) to yield the spectrum of the medium magnetization fluctuations. The resulting spectral shape approximately fits a simple Lorentzian form. Fluctuation correlation length and variance are easily determined for all states of medium magnetization. Noise power data are compared to the results of in-situ remanence measurements. DC current applied to the recording head produced the uniform magnetization states for which the noise was analyzed. The remanent magnetization corresponding to each current was determined by recording long-wavelength square waves utilizing the same current amplitude that produced the uniformly magnetized state

Keywords

magnetic heads; magnetic recording; magnetisation; noise; remanence; DC current; Lorentzian form; amplifier gain; current amplitude; fluctuation correlation length; gap loss; head differentiation; in-situ remanence measurements; long-wavelength square waves; magnetization fluctuations; noise power spectrum; playback effects; recording head; spacing loss; spectral shape; uniformly magnetized thin-film recording media; Fluctuations; Gain measurement; Loss measurement; Magnetic heads; Magnetization; Noise measurement; Noise shaping; Power measurement; Spectral shape; Transistors;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/20.102901

Filename

102901