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 CrO
2
tapes, 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.