Title :
Measurement of the switching speed limit in high coercivity magnetic media
Author :
Doyle, W.D. ; He, L. ; Flanders, P.J.
Author_Institution :
Dept. of Phys., Alabama Univ., Tuscaloosa, AL, USA
fDate :
11/1/1993 12:00:00 AM
Abstract :
A microstripline pulse field system that allows the switching speed of high coercivity magnetic media to be measured with pulse widths t⩾0.64 ns is discussed. The results for γFe2O3 are in good agreement with the previous work of Thornley and Williams (1974). A DC bias field HB was added to the pulse field to allow the high coercivity samples to be switched from saturation to zero remanence and the results analyzed in terms of the switching constant Sw. At HB=400 Oe, Sw(Co-γFe2O3)=158 ns-Oe; at HB=700 Oe, SW (barium ferrite)=135 ns-Oe; at HB=720 Oe, SW (metal particle)=84 ns-Oe. The value of SW increased with decreasing bias field, particularly for barium ferrite, indicating that in zero bias barium ferrite tapes it would be a factor of three slower than metal particle tapes
Keywords :
barium compounds; cobalt; coercive force; ferrites; iron; magnetic properties of fine particles; magnetic recording; magnetic switching; magnetic tapes; remanence; BaFe12O19; Co-Fe2O3; DC bias field; Fe particles; high coercivity magnetic media; magnetic recording; metal particle tapes; microstripline pulse field system; remanence; switching constant; switching speed limit; Barium; Coercive force; Ferrites; Magnetic field measurement; Magnetic switching; Microstrip; Pulse measurements; Saturation magnetization; Space vector pulse width modulation; Velocity measurement;
Journal_Title :
Magnetics, IEEE Transactions on
