Observation of magnetic domains of magnetic recording medium

Using the colloid-SEM technique for observing minute magnetic domains, combined with the gas evaporation method where high resolution was needed, an attempt was made to observe the magnetization profile through a magnetically recorded S-VHS tape in order to analyze the recording magnetization pattern produced by the application of an external magnetic field. From this, simultaneously with the first observation of the magnetization pattern of a dual wavelength superimposed recording, it was found that, with the short wavelength of the recorded magnetization, the observed magnetization decreases and, moreover, it became clear that, with respect to the short wavelength region, it is of the same magnitude as the recorded wavelength.