Perpendicular write-head remanence characterization using a contact scanning recording tester

In this study, an experimental method for characterizing perpendicular write-head pole-tip remanence using a contact scanning recording tester is presented. The head remanence is characterized by imaging the written patterns generated by perpendicular write heads on dc-saturated perpendicular media. Write-head footprints are recorded with pulsed unidirectional currents while the head is stationary, followed by scanning the head in various directions at current-off state. Sufficient head remanent field yields written traces during the current-off scan. Projection of traces in multiple scanning directions enables pinpointing of the pole-tip remanence locations. It is found that the traces written by the remanent field appear only when pulse current amplitudes exceed a certain threshold value. The strength of remanent field also shows a dependence on current pulse polarity. The "stiffness" of the remanence is characterized by the amplitude of the opposite write current needed to eliminate the remanent field. (c) 2005 American Institute of Physics.