In situ investigation of the magnetic domain wall in Permalloy thin film by Lorentz electron microscopy

Study of thermally evaporated thin permalloy films by the Fresnel mode of TEM and AFM

“…Refs. [2][3][4][5][6][7][8][9][10][11][12]). For example, Gentils et al [11] reported the presence of cross-tie walls in 17.5 nm thick permalloy films, while earlier studies showed that the mentioned walls occur for the film thickness in the range from 30-40 nm to 90-100 nm [13,14].…”

Measurement of the remnant magnetic-field in Lorentz mode using permalloy

“…By tilting the specimen, as seen in Fig. 2, the resulting in-plane component of the remnant magnetic field causes a movement of the circle Bloch line [14,15] .…”

Characterization of magnetic domain walls using electron magnetic chiral dichroism

“…The Neel wall is spaced at regular intervals by short cross Bloch lines, denoted as 'cross ties', each terminating in a free end as shown in figure 1(a). Domain wall creeping of the circle-tie walls is connected with circular Bloch line movements and a variation of the main wall curvature [8,9]. …”

“…Most methods used for this purpose, such as Bitter powder technique, magneto-optical Kerr effect, Lorentz microscopy, electron holography, magnetic force microscopy and x-ray topography, have insufficient selectivity or spatial resolution to directly relate the microstructure and magnetic character of individual domain walls [5][6][7]. In our previous work, the movement of the circular Bloch line was studied by in situ Lorentz microscopy [8,9]. The magnetic contrast of Lorentz microscopy is based on the Lorentz force, which can only be used to identify the in-plane domains and Neel walls with magnetization orientation in the plane of a thin film.…”