An extended version of the Gibbs adsorption isotherm, which included dislocations and vacancies, was used to analyse existing experimental data. Phenomena and models such as solid-solution softening, H-enhanced local plasticity, hydride brittleness and super-abundant vacancies could be interpreted in terms of thermodynamics as caused by changing the defect energy by solute segregation. As in Gibbs’ original work, the surface and grain-boundary energies were reduced by excess solute.

Reducing Grain Boundary, Dislocation Line and Vacancy Formation Energies by Solute Segregation II - Experimental Evidence and Consequences. R.Kirchheim: Acta Materialia, 2007, 55[15], 5139-48