Observation of magnetic-domain states of barium ferrite particles by electron holography

Abstract

Magnetic domain states of completely isolated particles of barium ferrite between 0.1 and 2 μm in size are investigated by electron holography. Phase distribution is reconstructed digitally by the Fourier transform method and converted to interference micrographs. In the interference micrographs single magnetic-domain particles are observed directly and clearly for the first time. Furthermore, it is found that single-domain and two-domain particles coexist down to sizes as small as about 0.1 μm.