Fig. 8: Mn chemical potential for bulk and different GBs.
From: Segregation-assisted spinodal and transient spinodal phase separation at grain boundaries
a The equilibrium chemical potential curves for the bulk and a GB with average atomic density ρGB = 0.75 at 450 °C are compared. The Maxwell construction is applied and the unstable sections of chemical potential curves are shown as dashed lines. Above the GB spinodal, segregation is accompanied with a transient spinodal phenomenon as discussed for the Fe–9 at.% Mn alloy. The range of bulk compositions/chemical potentials for transient GB spinodal are marked with the two-sided black arrows. b The chemical potential curves for different GB density values (representing different GB types) are compared. Depending on the GB atomic density, the GB free energy density, the chemical potential and hence the coexistence of the bulk and GB can change.
