Field sweep rate dependence of media dynamic coercivity

The dependence of the media dynamic coercivity dependence on field sweeping rate was obtained for a general case with the media energy barrier /spl Delta/E=K/sub u/V(1-H/H/sub 0/)/sup n/. The effective coercivity measurement time t/sub eff/ for a linearly sweeping field is derived. The general solution was applied to perpendicular media (n=2). The difference in perpendicular media coercivity with a step field and linearly sweeping field is calculated for various H/sub 0/ and K/sub u/V/(k/sub B/T). The dynamic coercivity of perpendicular media samples was measured using a Kerr-effect magnetometer with both field sweep rate and finite time duration schemes. The calculated coercivity is compared to measurement results.