SEGREGATION ENERGIES OF PHOSPHORUS AND SULFUR IN VARIOUS RELAXED STRUCTURES OF GRAIN BOUNDARIES IN Ni BY TIGHT-BINDING APPROXIMATION

A. Larère , M. Guillopé , K. Masuda-Jindo

Grain boundary segregation of sp-valence impurities in Ni have been investigated using a tight-binding type electronic theory of s, p and d-basis orbitals. Two center integrals both for host and impurity atoms are determined within Harrison's universal scheme. The relative electronic energy levels Es, Ep and Ed of s, p and d basis orbital are taken from atomic structure calculations by Herman and Skillman and sp-valence impurities are assumed to be electrically neutral. Segregation energies are calculated for phosphorus and sulfur at Σ = 5 (210), Σ = 5 (310), Σ = 11 (310), Σ = 11 (113) grain boundaries, the structure of which was first relaxed by a quasi-dynamical technique. Our results show a qualitative agreement with experimental data of P and S segregation.

Domaines: Articles anciens

A. Larère, M. Guillopé, K. Masuda-Jindo. SEGREGATION ENERGIES OF PHOSPHORUS AND SULFUR IN VARIOUS RELAXED STRUCTURES OF GRAIN BOUNDARIES IN Ni BY TIGHT-BINDING APPROXIMATION. Journal de Physique Colloques, 1988, 49 (C5), pp.C5-447-C5-450. ⟨10.1051/jphyscol:1988554⟩. ⟨jpa-00228051⟩