CRYSTALLIZATION OF AMORPHOUS FE78B13SI9 RIBBONS AS MONITORED BY MOSSBAUER-SPECTROSCOPY

The crystallization of amorphous Fe78B13Si9 ribbons is monitored throu gh the evolution of the hyperfine fields at the Fe sites as the ribbon s are annealed between 300 degrees C and 550 degrees C for two hours a t intervals of 50 degrees. Mossbauer sextets belonging to alpha-Fe(Si) . Fe3B, Fe2B and alpha-Fe compounds begin to be seen as the annealing temperature is raised past 400 degrees C. The hyperfine field distribu tions responsible for the broadening of the Mossbauer sextet associate d with the amorphous phase appear to be bimodal in nature. It is seen that the range of hyperfine field values becomes narrower as the annea ling temperature is raised, pointing to a lessening of the inhomogenei ty of the amorphous phase. (C) 1998 Elsevier Science Ltd. All rights r eserved.