Title :
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
fDate :
9/1/1999 12:00:00 AM
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;
Journal_Title :
Magnetics, IEEE Transactions on
