Effect of media properties on side erase bands

The erase bands on CoNiCr/Cr longitudinal media with coercivities ranging from 176 to 1390 Oe have been studied using a two-frequency, triple-track profile method. In this method, the two side tracks are recorded at 10 kfci and the central track ranges from 0 to 40 kfci. The write and the erase widths are measured by the Bitter method. Media properties such as coercivity, coercivity squareness, and remanence-thickness product are correlated with the total write width. It is shown that media with high coercivity squareness contribute to a reduction in the width of a side erase band. The magnetic structure of the triple-track profile has been characterized by high-resolution Bitter patterns using scanning electron microscopy, showing domain structures within bit cells and along track edges. The relationship of the erase band to the magnetic structure is discussed.>