A thermodynamic study was made of solid interfaces, and the effect of a high quasi-hydrostatic pressure of about 1GPa upon the interfacial segregation of Bi was characterized. At a pressure of 1atm, and at sub-eutectic temperatures, the grain boundaries in Bi-saturated material exhibited near-monolayer levels of Bi segregation that were characterized by a segregation enthalpy of about 0.67eV/atom. On the other hand, under a pressure of about 1GPa the segregation was almost completely suppressed. Segregation, and pressure-induced de-segregation, were highly reversible; with the source or sink for Bi being a Bi-rich secondary phase that was located at multiple grain junctions. A greater specific volume, due to Bi segregation, was associated with charge-compensating point defects.

J.R.Lee, Y.M.Chiang, G.Ceder: Acta Materialia, 1997, 45[3], 1247-57