Magnetic structure determination for Nd90-xFexAl10 glassy hard magnets using RMC modelling of neutron diffraction data

Considering experimental magnetic results and local magnetic structures, simulated by the reverse Monte Carlo method using neutron diffraction data, we propose that the microstructure of the Nd-Fe-Al glassy alloys, which is intimately related to their magnetism, consists of small clusters or medium-range ordered regions of 2-3 nm, embedded in an amorphous matrix. The distribution of the clusters is more homogeneous in thick samples, leading to a higher magnetic percolation limit and an increase of the coercive field from 1 to 2 T for thin samples 25 μm in thickness to 7-8 T for thick samples 2 mm in diameter