Magnetic Domains of Cobalt Single Crystals at Elevated Temperatures

By means of the enhanced magneto‐optic Kerr effect the magnetic‐domain structure of cobalt single crystals is investigated in the temperature range from 20° to 400°C. Cobalt is of special interest for the theory of domain structures, since the strongly temperature‐dependent anisotropy constant $K_1$ induces uniaxial anisotropy at low temperatures, and conical and planar anisotropy at higher temperatures. While the domain patterns in the uniaxial case are now rather well understood, the continuous variation of $K_1$ gives an access to the understanding of the structures of the conical and the planar anisotropy. The observed domain patterns are analyzed and an interpretation of the main features, especially of those which are connected with internal stresses, is given.