Chemical heterogeneity of MMP magnets compared to the chemically homogeneous SMP ones. Schematics in (a) and (c) show the evolution of different microstructures for SMP and MMP magnets, respectively. Back-scattered SEM micrographs (bright and grey contrasts refer to RE-rich and matrix phases, respectively) and corresponding elemental mappings of Nd, Ce, and La for (a) MMP magnet with 18 wt.% La–Ce/TRE and (b) SMP magnet with 9 wt.% La–Ce/TRE. (e) Room temperature demagnetization curves for SMP and MMP magnets. (f) Dependence of magnetic properties on La–Ce concentration for SMP and MMP magnets.^[22]