On the Correlation between Domain Size and Coercive Force in Grain-oriented 3.25% Si-Fe

A method is described for measuring the size of the largest spike-shaped magnetic domains on surfaces of grain-oriented 3.25% Si-Fe. Values of coercive force, obtained by using measured spike-domain size in a previously derived empirical expression correlating spike size with the coercive force in silicon-iron, are in close agreement with coercive force values obtained from B-H loop measurements. This technique makes it possible to measure the coercive force on non-toroidal magnetic components used in data processing machines.