کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1449858 988716 2007 14 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Grain boundary segregation, stress and stretch: Effects on hydrogen absorption in nanocrystalline palladium
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد سرامیک و کامپوزیت
پیش نمایش صفحه اول مقاله
Grain boundary segregation, stress and stretch: Effects on hydrogen absorption in nanocrystalline palladium
چکیده انگلیسی

We present a combined experimental and theoretical study of hydrogen solubility at equilibrium in nanocrystalline Pd. We find that the elastic interaction between the grain boundaries and the crystal lattice has important consequences for the adsorption isotherms at small grain size. In α-Pd–H (the dilute solution), the superficial hydrogen density Γ at the grain boundaries is positive, thereby causing tensile stress, as well as an increase in the H fraction in the lattice (when compared with bulk Pd–H). In α′-Pd–H (the concentrated solution), Γ is negative, the stress is compressive and the lattice is depleted of H. We report values for the thermodynamic parameters that quantify the forces and the deformation of the grain boundaries, the interface stress and stretch, respectively. Their values are also of opposite sign for the two phases. Our results for the grain boundary adsorption isotherms imply enrichment or depletion in a layer that is much wider than the structural core of the grain boundary.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Acta Materialia - Volume 55, Issue 4, February 2007, Pages 1241–1254
نویسندگان
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