Magnetic Properties of Interference Pulsed Laser Heated Fe-Based Amorphous Ribbons

The influence of pulsed laser interference heating on structure and magnetic properties of Fe-based (FeSiB) amorphous ribbons is reported. This form of heating results in periodically placed laser heated micro-areas. In these, changes in microstructure and magnetic properties occur and the results are compared with those for samples after conventional annealing at 600 degrees C. Electron microscopy showed that the laser beam energy causes partial crystallization of the amorphous material, which affects magnetic properties. Magnetic hysteresis loop measured by SQUID magnetometer showed that saturation magnetization sigma lowered after both treatment (i.e., conventional annealing and laser heating) in comparison to amorphous ribbons (where the range of sigma was from 155 to 185 emu/g), except for FeCuSiB alloy after laser heating. Magnetic structure of all the samples was also observed by magnetic force microscopy. While no signal was detected in the as-received amorphous ribbons, conventional annealing and laser heating resulted in strong magnetic signals.