Temperature dependence of wall-energy anisotropy in orthoferrites

The hypothesis that in orthoferrites walls parallel to the axis are Bloch walls while walls parallel to the axis are Néel walls is investigated by measuring the wall-energy anisotropy as a function of the quality factor by varying the temperature of the sample. One of the methods of measuring the temperature dependence of uses vibrating sample magnetometer measurements. Also, a simple method for obtaining the temperature dependence of and the material characteristic length using an isolated bubble domain without collapsing it is described. It is found that at high temperatures, where is large, the wall-energy anisotropy increases asymptotically to approximately 3.8 percent of the average wall energy, presumably due to a difference in exchange interactions aloug different crystalline axes. The measurements seem to verify the predicted dependence of wall-energy anisotropy on and the hypothesis.