QUANTITATIVE-EVALUATION OF A THIN-FILM RECORDING HEAD FIELD USING THEDPC MODE OF LORENTZ ELECTRON-MICROSCOPY

The quantitative evaluation of the recording head field is an importan t aspect of the goal of increased areal density of data storage in mag netic recording. The differential phase contrast (DPC) mode of Lorentz electron microscopy has been used to determine the stray field from a thin film recording head and this has been achieved by collection of data sets suitable for tomographic reconstruction. By etching part of the alumina present in the vicinity of the poletips it has also proved possible to identify magnetic flux escaping from regions of the poles , other than the poletips, and to investigate the contribution these m ake to the head field profile as a function of dc drive current.