Frequency and transient response of yoke flux for 45/55 NiFe and CoTaZr thin film write heads

Author

Jury, Jason ; George, Peter ; Judy, Jack H.

Author_Institution

Center for Micromagnetics & Inf. Technol., Minnesota Univ., Minneapolis, MN, USA

Volume

35

Issue

5

fYear

1999

fDate

9/1/1999 12:00:00 AM

Firstpage

2508

Lastpage

2510

Abstract

This paper describes measurement and modeling of the frequency and transient response of the yoke flux in plated 45/55 NiFe and amorphous CoTaZr thin film write heads. The frequency response of the flux was determined from impedance measurements without any assumptions about the form of magnetic impedance. The transient response was calculated (i) from the frequency domain response using a inverse Fourier transform and (ii) from the frequency and inductance-current measurements using a nonlinear eddy current model. In all cases, the CoTaZr head showed better high-frequency and highspeed response than the 45/55 NiFe head. In addition, at higher DC bias currents (>60 mA) the CoTaZr flux frequency response shows spin dynamic damping; the NiFe head flux response shows only eddy current damping for all measured bias currents,

Keywords

amorphous magnetic materials; cobalt alloys; eddy currents; equivalent circuits; frequency response; iron alloys; magnetic flux; magnetic heads; magnetic thin film devices; nickel alloys; tantalum alloys; transient response; zirconium alloys; 60 mA; CoTaZr; DC bias currents; NiFe; amorphous CoTaZr thin film write heads; eddy current damping; frequency measurements; frequency response; high-speed response; impedance measurements; inductance-current measurements; inverse Fourier transform; magnetic impedance; nonlinear eddy current model; plated 45/55 NiFe thin film write heads; spin dynamic damping; transient response; yoke flux; Amorphous materials; Current measurement; Damping; Eddy currents; Frequency measurement; Frequency response; Impedance measurement; Magnetic heads; Transient response; Transistors;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/20.800874

Filename

800874