Pulse response of recording media

The response of magnetic tapes to field pulses of durations down to 0.68 ns was measured. The tapes examined included: gamma iron-oxide, cobalt-substituted gamma iron-oxide, chromium-dioxide, and cobalt-phosphorus in particle and continuous film form. The majority of tapes showed a fairly linear relationship with switching speed constants from 0.2 to 0.6 us-Oe when reciprocal time was plotted against pulse field amplitude. No correlation was observed between the response speeds and the common physical or magnetic properties of the tapes. The pulse fields were generated from a strip-line recording head whose response was flat from dc to 3 GHz.