Fig. 1
From: A machine learning approach to model solute grain boundary segregation
Grain boundaries, their energies, and segregation energy distributions. The polar plot in the middle shows the GB interfacial energies for 38 different boundaries in the boundary-plane fundamental zone for pure Al 53.1°[001] boundaries with different normal vectors (see text). The energy distributions when substituting a Mg atom at the various GB sites are shown for selected boundaries below and above the polar plot. The blue bars are the data from a binning analysis. The blue curve shows the smoothed distribution. The black vertical dashed line in these plots marks the energy where a Mg atom has the identical energy as a Mg atom substituted in bulk. Thus, all energies left of this line represent sites attractive (exothermic) for segregation while the ones to the right represent sites which are not attractive. To the right of the polar plot, the atomic structure for two high-symmetry tilt boundaries projected on the [001] plane is shown. GB sites as identified by Common Neighbour Analysis (CNA) are shown in orange. For the (310) boundary the four inequivalent sites are labelled from I to IV
