Domain Studies in Thin Film Recording

Abstract

An observation technique utilizing the longitudinal Kerr magneto-optic effect was used in various studies of thin film recording. The semitransparent nature of the recording media allowed simultaneous observation of recorded domains and the write and read head gaps. Thin film heads were used to record in iron films having coercivities ranging from 60 to 160 Oe. The apparatus allowed quick determinations of maximum linear densities which were as high as 1550 flux reversals/cm. Recorded domain orientation with respect to the gap of a thin film read head was easily observed, and the corresponding output signals on an oscilloscope were photographed. The write-read-observe apparatus with a thin film read head was also helpful in detecting the magnetic field from Néel walls.