Fig. 5: Electron transport and magnetization reversal of the MOS.

a Experimental temperature rise curves (left) and temperature distribution images (right) of the MOS, HS, and the state-of-the-art commercial SmCo₅, Sm₂Co₁₇, and NdFeB in an alternating magnetic field. b Experimental data and model fitting of temperature-dependent electrical resistivity of the MOS. c Electrical resistivity enhancement along gradient direction of the MOS. d Four models in the simulations represent single-phase NdFeB (SP), NdFeB/α-Fe composite (COM), NdFeB/α-Fe composite with core-shell (CS) structure, and MOS sandwich core-shell (SCS) structure. e Electrical resistivity calculated by simulations with different models, as well as the corresponding resistivity measured in single-phase NdFeB (represents SP), Nd₂Fe₁₄B/α-Fe prepared by melt spinning (represents COM), surface of the GS Nd₂Fe₁₄B/α-Fe with a core-shell structure (represents CS), and surface of the MOS (represents SCS). f Initial magnetization curves (left) and their corresponding differential curves (right) of the MOS and HS. g Applied field dependence of H_c (left) for the MOS and HS, along with their corresponding differential curves (right) of the MOS and HS. The primary pinning field H_p is indicated in (f) and (g).