Laser patterning of Fe-Si-B amorphous ribbons in magnetic field

Site-specific nano-crystallization in an amorphous soft magnetic Fe-Si-B alloy was induced via laser processing on a magnetic substrate. The microstructure evolution was characterized using site-specific transmission electron microscopy, and the results are rationalized by diffusion-based calculations. A clear variation in grain-size and spatial distribution is observed at the center region compared with edge regions of the laser track. Additionally, the nano-crystalline phase exhibits a crystallographic texture at the edge region, whereas a random texture is obtained at the center of the laser track. The evolution of structure, size, and morphology of grains are explained by the influence of magnetic field-enhanced thermal effect on nucleation rate during crystallization.