Observation of Magnetization of Obliquely Evaporated Co-CoO Magnetic Recording Tape

Electron holography of magnetic materials

“…The elemental mapping by Ito et al [51] has revealed that the columns containing Co crystallites, the diameter of which is a few dozen nanometres, are surrounded by the CoO crystallites. The two rectangles in figure 24(a A magnetic flux map of a recorded Co-CoO tape, the bit length of which was 250 nm, was observed by electron holography by Xia et al [52]. Figure 25 shows reconstructed phase images of (a) the outside and (b) the inside of the sliced specimen, in which the phase shift is represented in terms of φ rather than cos(φ).…”

“…More importantly, the flux loops are oblique due to the tilted columnar structure of the Co crystallites. Xia et al [52] performed intensive computer simulations of the remanent state of a recorded Co-CoO tape. Figure 26 shows a simulated reconstructed phase image, in which the lines of magnetic flux both outside and inside the specimen are given.…”

Advanced Electron Holography Applied to Electromagnetic Field Study in Materials Science

“…Furthermore, the three‐dimensional (3D) observation of magnetic vortex cores in stacked ferromagnetic discs has been achieved . In addition, the magnetic flux distributions in the interior and exterior of magnetic recording tapes and magnetic recording heads have been analyzed in detail for better understanding of their magnetic properties and performances.Electron holography can also be used for correcting lens aberrations as well as for observing electric fields, electrostatic potentials, strains, and biological specimens . In heterostructures, direct observations of two‐dimensional (2D) electron gas have been performed .…”