Remanent Domain Structures of BaFe12O19

Abstract

In order to investigate the magnetizing process of uniaxial oxides, the remanent domain structure of a thin single crystal of BaFe₁₂O₁₉ was observed on the basal plane by means of Faraday effect. Three kinds of remanent domains—radial, maze, and honeycomb—were found, when the field was reduced to zero along the c axis from saturation. When the angle θ between the c axis and the magnetizing field was changed from 0° to 90°, the remanent domains lost their characteristic and altered to maze, parallel, honeycomb, and finally to a mixed structure of honeycomb and parallel domains. These changes are discussed from the magnetizing process based on the critical field diagram and it is suggested that the critical field can be determined as a field where the remanent structure changes into a saturated state. The anisotropy field 2K/I_s of BaFe₁₂O₁₉, obtained as the critical field at θ = 90°, was 17 000 Oe and showed good agreement with the previously reported value.