Mössbauer and Kerr Microscopy Investigation of Crystallization in FeCoB Ribbons.

The present work reports the crystallization study of amorphous FeCoB ribbons using x-ray diffraction, 57Fe Mössbauer spectroscopy in transmission mode and magneto-optical Kerr (MOKE) microscopy. Annealing at 673 K is found to result in crystallization. From the Mossbauer measurements it is observed that the Fe magnetic moments are in the plane of sample for as-cast ribbon; α-FeCo, (Fe0.5Co0.5)2B and Fe2B phases are formed after crystallization. MOKE microscopy revealed that wide 180° domain walls & narrow fingerprint domains are observed before crystallization and fine domains are observed after crystallization. The results are explained in terms of the presence of internal stresses and their annealing with thermal heat treatment. [ABSTRACT FROM AUTHOR]