Infrared laser annealing of nanocomposite Nd–Fe–B/Mo/FeCo multilayered magnet films

The formation of nanocomposite Nd-Fe-B/Mo/FeCo multilayered magnet films using the infrared laser annealing technique. The perpendicular magnetic anisotropy of the film with Mo interlayer was larger than that of the film without Mo interlayer before annealing. Magnetic properties of both films were drasticly changed from soft magnetism to hard magnetism with in-plane magnetic anisotropy after the infrared laser annealing process at 760°C. Coercivity of in-plane annealed film with Mo interlayer was about 10 kOe which was double that of the film without Mo interlayer. In second quadrant, squareness of demagnetization curve of infrared laser annealing processed film with Mo interlayer was better than that of film without Mo interlayer. The infrared laser annealing process crystallizes the amorphous phase of the Nd-Fe-B layer as well as the multi-step annealing, even though the infrared laser annealing process time is only 1/100 of the process time of the multi-step annealing using halogen lamps reported previously.