Effects of topography on the local variation in the magnetization of ultrasoft magnetic films:a Lorentz microscopy study

This paper concentrates on a detailed analysis of Lorentz transmission electron microscopy (LTEM) observations in the study of the magnetic properties of soft magnetic films. Besides ripple fringes in the LTEM image that are commonly observed in nanocrystalline soft magnetic films, there also appears a dotted contrast along the ripple fringes. A theory of LTEM images for films with one-dimensional and two-dimensional (2D) periodic topographies, in combination with the micromagnetic oscillations of the magnetization, is presented. The theory predicts the 2D pattern in LTEM in agreement with experimental observations.