A dynamic study of domain formation mechanism during thermomagnetic recording based on micro-Hall effect measurements

A method for analyzing the dynamics of domain formation during the thermomagnetic recording process has been developed based on the extraordinary Hall effect.^1,2 A magnetic domain is written at the center of a cross-shaped magneto-optical sample having an area of 5×5 μm², and the Hall voltage is monitored during the recording process. As far as domain nucleation is concerned, we find that the temperature gradient around the transition region (i.e., the region whose temperature is between the critical temperature for magnetization reversal and the Curie point) is very important. Under the conditions of high power and short pulse-width laser, a domain can form only during the cooling period. However, it is possible for a domain to form during the heating cycle under a low power, long pulse laser beam.