Head Parameter Sensitivity Study Of The Intrinsic Field Reversal Time

Studies to establish the key head sensitivity parameters affecting the intrinsic field reversal time are reported. The effect of supply voltage, eddy current damping, head moment, and turns are investigated using the nonlinear, eddy current damped, thin-film write head model proposed by Klaassen and Hirko [IEEE Trans. Magn. 32, 3524 (1996)]. The model is realized using PSPICE circuit simulation. Eddy current time constant dependencies derived by Wood, Williams, and Hong [IEEE Trans. Magn. 26, 2954 (1990)] are used to explore materials with magnetizations ranging from 4 pi M-S=10-20 kG, resistivities of 25 and 125 mu Omega-cm and heads with 10-15 turns. Confirmation of the above writer sensitivities has been investigated using a short yoke 37 turn, high moment, low eddy current CoTaZr inductive head. From the experimentally determined model parameters, rise time results are computed for an improved 10 turn writer design. The results are shown to approach or exceed the limiting dynamics of the spin system. (C) 1999 American Institute of Physics. [S0021-8979(99)30508-9].