The hard magnetic properties and microstructure evolution of the multilayer NdFeBNbCu/FeBSi centre dot n thin films

摘要

The influence of the thickness of constituent layers and annealing conditions for multilayer [NdFeBNbCu/FeBSi] centre dot n thin films on the magnetic properties and microstructure is reported. The Nb-Cu combination inhibits the grain growth and promotes the formation of nucleation sites. The FeSiB layer insertion leads to a slight increase in the Curie temperature and to a rectangular hysteresis loop. As compared to Ta/NdFeBNbCu (540 nm)/Ta single layer, the Ta/[NdFeBNbCu (180 nm)/FeBSi (15 nm)] centre dot 3/Ta multilayer nanocomposite films exhibit very good magnetic properties such as squareness M_r/M_s of about 0.92, maximum energy product of about 397 kJ/m~3, and an increase in the Curie temperature of about 17 deg C due to stratification by using FeBSi film as space layer.