Observation of magnetic head fields using distorted transmission electron microscopy images

We have observed magnetic fields generated from a thin film magnetic head using transmission electron microscopy (TEM) images. The image in which the shadow of the head appears together with the projected pattern of a reference film is acquired with the use of appropriate defocus. From the pattern distortion in the image, both strong and weak components of the head field can be detected. Furthermore, this method makes it possible to quantitatively analyze, with high spatial resolution, the magnetic field strength which depends on distance from the air bearing surface of the head.