Electron holography of magnetic materials

Abstract

Electron holography, which visualizes magnetic and/or electric fields in materials on the nanometre scale, is a powerful tool for the study of fundamental issues in physics as well as the characterization of advanced materials. This paper presents an overview of recent electron holography studies on advanced magnetic materials, which include hard magnetic materials (both nucleation-type and pinning-type magnets), soft magnetic materials (both classical alloys and recently developed nanostructured materials), magnetic recording materials (Co–CoO tape and other related topics) and magnetic functional materials (ferromagnetic shape memory alloys and colossal magnetoresistive manganites).

Study of obliquely deposited thin cobalt films

“…Depending on the type of application, oblique deposition is successfully used to tailor the film properties. The range of applications is very wide and includes, for example, metal evaporated video tapes (which consist of partially oxidized Co 80 Ni 20 or Co) [1,2], giant magnetostrictive films [3], optical filters, field emitters, solar cells, thermal barrier coatings, high-speed gas sensors and chromatography based microfluidic devices [4].…”

Observations of charge-ordered and magnetic domains in LuFe2O4using transmission electron microscopy

“…Information on the magnetic domain structure was obtained using the method of electron holography, which enables observations of the in-plane component of the magnetic flux. 28 The electron holograms were obtained using a 300-kV transmission electron microscope (JEM-3000F, JEOL).…”

Near-Curie magnetic anomaly at the Ni/C interface observed by electron holography

“…EH has been widely employed in recent years for studying magnetism at the sub-micron scale in its many forms, for example, in characterization of the domain structure in magnetic thin films [2,3], measurement of domain wall widths [4] and magnetic vortices [5,6], induction mapping in arrays of nanoparticles [7][8][9], and study of magnetic behavior in nanopatterned arrays and individual magnetic elements [10].…”