Quantitative evaluation of a thin film recording head field using the DPC mode of Lorentz electron microscopy

The quantitative evaluation of the recording head field is an important aspect of the goal of increased areal density of data storage in magnetic 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 make to the head field profile as a function of dc drive current