Fig. 5: The origin of the nearest neighbor Co atoms on Al diffusion by first-principles calculations.

a The migration path of the exchange between a lattice atom and a nearby vacancy. b Migration barrier of an Al atom with the increase of the number of the nearest neighbor Co atoms (0, 4, 8, and 16). c Relative energy changes when an Al is moved towards a Co atom under different Co environments. d, e ELF plot in a [100] plane corresponding to the case of c at different numbers of the nearest neighbor Co atoms. Note that ELF = 0 and 1 represent the completely delocalized and perfect localization of electrons, respectively. Color scale of the ELF value difference ranges from 0 to 0.2.