title: Foucault imaging and small-angle electron diffraction in controlled external magnetic fields.
abstract: We report a method for acquiring Foucault images and small-angle electron diffraction patterns in external magnetic fields using a conventional transmission electron microscope without any modification. In the electron optical system that we have constructed, external magnetic fields parallel to the optical axis can be controlled using the objective lens pole piece under weak excitation conditions in the Foucault mode and the diffraction mode. We observe two ferromagnetic perovskite-type manganese oxides, La0.7Sr0.3MnO3(LSMO) and Nd0.5Sr0.5MnO3, in order to visualize magnetic domains and their magnetic responses to external magnetic fields. In rhombohedral-structured LSMO, pinning of magnetic domain walls at crystallographic twin boundaries was found to have a strong influence on the generation of new magnetic domains in external applied magnetic fields.
authors: Department of Materials Science, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan.
authors: Hiroshi
authors: H
authors: Nakajima
authors: Department of Materials Science, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan.
authors: Atsuhiro
authors: A
authors: Kotani
authors: Department of Materials Science, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan.|Center for Emergent Matter Science, The Institute of Physical and Chemical Research (RIKEN), Hatoyama, Saitama 350-0395, Japan.
authors: Ken
authors: K
authors: Harada
authors: Department of Materials Science, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan.
authors: Yui
authors: Y
authors: Ishii
authors: Department of Materials Science, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan mori@mtr.osakafu-u.ac.jp.
authors: Shigeo
authors: S
authors: Mori
keywords: Foucault imaging; Lorentz microscopy; Small-angle electron diffraction (SmAED); magnetic deflection; magnetic domains; perovskite manganese oxide