High frequency characterization and recording performance of NiFe and laminated FeN heads

Author

Hu, H.L. ; Weresin, Walt E. ; Home, D. ; Gallagher, T. ; Robertson, N. ; Re, M.

Author_Institution

IBM Corp., San Jose, CA, USA

Volume

32

Issue

5

fYear

1996

fDate

9/1/1996 12:00:00 AM

Firstpage

3530

Lastpage

3532

Abstract

A simple high frequency characterization technique extended from DC disk erasure is presented to measure the write field degradation for frequencies up to 500 Mfc/s (250 MHz) on plated NiFe and sputtered laminated FeN heads. The results show that eddy currents appear to be the main cause for high frequency write field degradation. Overwrite recording measurements, which may be used to approximate the non-linear write effects, also indicate that FeN heads, despite low efficiency, may be adequate for writing up to 100 MHz on a disk with a coercivity of 2500 Oe. This disk is capable of supporting 5-10 Gb/in² densities

Keywords

eddy current losses; hard discs; iron alloys; iron compounds; magnetic heads; magnetic multilayers; magnetic recording noise; magnetic thin film devices; nickel alloys; soft magnetic materials; 1 to 250 MHz; Al₂O₃ lamination; DC disk erasure; FeN-Al₂O₃; NiFe; coercivity; eddy current loss; high frequency characterization; nonlinear write effects; overwrite recording measurements; plated NiFe heads; pulsed erasure measurements; recording performance; sputtered laminated FeN heads; write field degradation; Coercive force; Degradation; Disk recording; Frequency; Magnetic heads; Pulse generation; Pulse measurements; Space vector pulse width modulation; Testing; Voltage;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/20.538680

Filename

538680