Automatic Measurement of Magnetic Domain and Bloch Wall Distributions on 3 Percent Si-Fe Sheet by Means of Hall Sensor

The authors describe apparatus for the highly accurate measurement of stray magnetic fields in a modification of Pfÿtzner´s method, and discuss the relation between the stray field distribution and basic 180° domains in (100), [001] 3 percent Si-Fe single-crystal sheets. A GaAs Hall element connected to a precision positioning device was used to detect normal field components on the sheet surface. The positions of Bloch walls, as determined by mapping from field measurements, agreed well with the positions from domain pattern photographs. The field was found to be greatest at the centers of domains, and the effect of scratching in reducing the stray field was also studied.