Experimental considerations on thermomagnetic characteristics of temperature-sensitive magnetic cores

Experimental results of the thermomagnetic characteristics of temperature-sensitive magnetic cores, such as flux density, coercive force and rectangularity of hysteresis loop, are discussed in this paper. The flux-density-versus-temperature characteristic, which changes at constant rate over a wide temperature range, was obtained. It was found that this behavior was caused by fluctuations in the concentration of imperfections present in the sample. An irregular relation between temperature and coercive force was observed in the vicinity of the Curie point. This drastic increase of coercive force is qualitatively explained by Kersten´s inclusion theory. Furthermore, the rectangularity of the hysteresis loop changes with temperature. In metal cores a slight increase of rectangularity was observed in the high-temperature region.