Domain wall structures in single crystal Fe films

The structure of 180° walls in single crystal Fe films has been examined by the defocussed mode of Lorentz microscopy. A clear asymmetric feature of the wall, which is characteristic to a two-dimensional 180° Bloch wall, was observed in the thickness range between 800 and 3200Å, proposed by theory. It is concluded that the 180° wall structure in the thickness range (I) from 800 to 1800Å is close to that of stray field free, but the structure in the thickness range (II) from 1800 to 3200Å deviates markedly from the one in the thickness range (I), as opposed to the theoretical prediction. Two models are proposed to account for the observed results.