MEASUREMENTS OF DOMAIN-WALL VELOCITY BY THE DARK-FIELD METHOD

A new method of measuring the velocity of domain walls (DWs) has been developed, to measure the moments at which the dark field image of the DW, in the form of a bright narrow strip of light, passes through tra nsparent slits. Details of measurements of the DW velocity in yttrium orthoferrite are described. The amplitude of the pulsed magnetic field is calibrated by direct comparison with a constant magnetic field. Su perposition of the dark field image on a reference laser beam may furt her increase the resolution of the measurements. The described method can also be used for magnetic field measurements.