Coercivity mechanism and microstructure evolution of perpendicular magnetic anisotropic Nd-Fe-B thick films annealed by pulsed laser

Pulsed laser annealing provides an effective solution to reduce the processing temperature of Nd-Fe-B thick films, which ensures compatibility with semiconductor processes and promotes its wide application in microelectromechanical systems. In this work, Nd-Fe-B thick films with a strong perpendicular magnetic anisotropy and a high magnetization are deposited at a processing temperature of 450 degrees C using a localized thermal treatment with an infrared pulsed laser. It is found that the c-axis columnar textures extending from the capping layer to the buffer layer are formed by the laser annealing. A micro-scale growth model for laser-annealed Nd-Fe-B thick films is established based on the relationship between their microstructure and magnetic properties. The evolution of magnetic domains and the first-order reversal curve indicate that the coercivity mechanism of the laser-annealed Nd-Fe-B thick films is primarily dominated by the nucleation, and the magnetic interaction is dominated by the dipole interaction. This work improves the low-temperature compatibility of Nd-Fe-B thick film deposition processes and promotes its application in microelectromechanical systems.