Electrophobic interaction induced impurity clustering in metals

• Published in: Acta materialia 2016-10, Vol.119, p.1-8
• Main Authors: Zhou, Hong-Bo, Wang, Jin-Long, Jiang, W., Lu, Guang-Hong, Aguiar, J.A., Liu, Feng
• Format: Article
• Language: English
• Subjects: Aluminum; Clustering; Clusters; Electrophobic interaction; Energy use; Hydrophobicity; Impurities; Impurity clustering; MATERIALS SCIENCE; Mathematical analysis; Metals; Solvents
• ISSN: 1359-6454; 1873-2453
• DOI: 10.1016/j.actamat.2016.08.005

We introduce the concept of electrophobic interaction, analogous to hydrophobic interaction, for describing the behavior of impurity atoms in a metal, a “solvent of electrons”. We demonstrate that there exists a form of electrophobic interaction between impurities with closed electron shell structure, which governs their dissolution behavior in a metal. Using He, Be and Ar as examples, we predict by first-principles calculations that the electrophobic interaction drives He, Be or Ar to form a close-packed cluster with a clustering energy that follows a universal power-law scaling with the number of atoms (N) dissolved in a free electron gas, as well as W or Al lattice, as Ec ∝ (N2/3−N). This new concept unifies the explanation for a series of experimental observations of close-packed inert-gas bubble formation in metals, and significantly advances our fundamental understanding and capacity to predict the solute behavior of impurities in metals, a useful contribution to be considered in future material design of metals for nuclear, metallurgical, and energy applications. [Display omitted]