MAGNETIC AND MAGNETOOPTIC PROPERTIES OF ORDERED BARIUM FERRITE FILMS PRODUCED BY RAPID THERMAL ANNEALING

A rapid thermal annealing (RTA) process has been developed that permits the preparation of well ordered films of barium ferrite (BaFe12O19) in minutes, rather than the hours conventionally required. Optical fluxes approximate to 40Wcm(-2) are used to produce linear heating rates up to 20 degrees Csec(-1) and achieve final sample temperatures in excess of 750 degrees C in less than one minute. Frequency and duty cycle modulation of the radiant optical energy allows close control of the heating cycle and the production of different RTA regimes. The magnetic and structural properties of the annealed samples have been shown to be dependent on the particular regime followed.