Lorentz electron microscopic studies on migration of bloch lines and buckling of cross-tie walls

Abstract

Domain wall creeping is connected with Bloch line movement under the influence of a hard‐axis field normal to the wall and with wall buckling under the influence of an easyaxis field parallel to the wall. These two phenomena are investigated separately by Lorentz microscopy. It is found that Bloch line migration along a cross‐tie wall occurs not only by Barkhausen jumps but also steadily over small distances. The smallest distances found between adjacent cross and circle Bloch lines are some 100 Å at transverse fields shortly below wall transition field strength. This transition from cross‐tie wall to Néel wall is marked by mutual neutralization of the Bloch lines which have approached each other. Contrary to the observations of Telesnin et al. and Torok et al. also wall bucklings are found which do not originate from cross Bloch lines and which have no apexes. Only at stronger easy‐axis fields the wall bucklings can become sometimes a zig‐zag line.

<I>In Situ</I> Lorentz Microscopy Observation of Displaced Chain Walls in Permalloy

“…[6][7][8] The circle Bloch line moved along the main wall between two cross-tie walls under the influence of an hardaxis field normal to the wall and the main wall curved by buckling of located parts of the wall under the influence of an easy-axis field parallel to the wall. We also observed the similar behavior of the usual cross-tie walls under applied magnetic field produced by the objective lens of TEM itself.…”

Electron microscopy of the magnetic structure of thin films

“…поведения границы с поперечными связями под действием поля вдоль ОЛН и ОТН наблюдались в работе 379 . Наблюдалось также сползание и границ Нееля 350 .…”