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Photographs of the Diffraction Pattern of Ferromagnetic CrBr 3
Author(s) -
Fischer F.
Publication year - 1969
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.19690310220
Subject(s) - monochromatic color , optics , perpendicular , diffraction , materials science , cryostat , condensed matter physics , physics , geometry , superconductivity , mathematics
Sharp diffraction patterns of the Fresnel type, which are free from distortion, have been photographed using monochromatic light and fixing the crystal to a 50 μm hole diaphragm cooled to 20 °K in an optical cryostat. Temporary saturation of the magnetization gives three different types of patterns according as the magnetic field forms an angle of 90, 45, or 0° with the crystal c ‐axis. Linearly polarized light gives interference spots of the first order polarized perpendicular to the primary light. An interpretation is presented considering also the circular dichroism. Second‐order spots polarized parallel to the primary light are probably due to the domain walls. Above an activation temperature of T A = 31.5 °K the domain walls become mobile. Hereby the 90° and the 45° type change into the 0° type. The latter also appears after cooling from above T C .