Horizontal Incidence Observation of Magnetic Fields in the Scanning Electron Microscope

A method for observing the leakage magnetic fields from recorded bits in magnetic media samples is described. When a primary electron beam is directed parallel to the surface of the sample, the Lorentz force resulting from the leakage field deflects electrons either toward or away from the sample surface; those deflected toward the sample strike the surface, generating secondary electrons. By scanning the surface with such a beam, secondary electron images showing the contrast of the magnetic leakage field may be obtained. It is shown that the images thus obtained are different for samples with perpendicular and with in-plane magnetization.