Local crystallization in amorphous Fe80Si11B9 ribbon by pulsed laser interference heating

Pulsed laser (Q-switched Nd:YAG) interference heating was used to create periodically distributed, crystallized, micro-areas, ∼10 μm in diameter within the amorphous matrix on Fe80Si11B9 alloy. Laser energy and a number of consecutive pulses were varied as controlled parameters of this study. The influence of such interference heating, on the resulting microstructure, magnetic domain structure and magnetic field was examined. TEM analysis showed that crystallized surface layer of the sample after pulsed laser heating consists of α-Fe(Si) nanocrystals embedded in the amorphous matrix. Research, using the Fresnel imaging (defocus mode) showed that the nanocrystallization of the amorphous alloy caused a significant refinement of the magnetic domain structure, as compared to amorphous state. The electron holography images show that the α - Fe(Si) crystallites introduce additional distortion of the magnetic field lines in the sample. The effects of an external magnetic field were studied by examining the configuration of the phase shift contours as a function of its magnitude.