ELECTRON HOLOGRAPHIC INTERFERENCE MICROGRAPH OF A SINGLE MAGNETIC-DOMAIN PARTICLE

Electron interference micrographs of a single magnetic-domain particle of barium ferrite are obtained experimentally and theoretically. In the experiment, a hologram of the particle with size about 1 mu m is recorded on film and the phase distribution of the object electron wave is reconstructed digitally by the Fourier transform method. In the theoretical calculation, the phase distribution is obtained by integrating the vector potential around the particle along the electron path, assuming that the particle is spherical and is in the single-domain state. The above two phase distributions are converted to interference micrographs where magnetic flux lines are observed, and compared with each other. The theoretically calculated result agrees well with the experimental one, proving that the particle is in the single-domain state.