Different methods of assessing switching field distributions of magnetic recording media

The width of the switching field distribution may be measured by the Williams-Comstock parameter 1 - S* or the relative difference between coercive forces CF. These two parameters are shown to be proportional, with constant slope, for many recording tapes measured in the parallel direction. For CrO2tapes, however, the constant of proportionality is anomalously low due to excellent alignment. Measurements at an angle to the tape direction are interpreted using a simple model. The parameter CF is shown to be consistent with typical shapes of static remanence curves.