Interstitial Solute Segregation at Triple Junctions: Implications for the Hydrogen Storage Properties of Nanomaterials

Fuente: arXiv
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Main Authors: Tuchinda, Nutth, Wagih, Malik, Schuh, Christopher A.
Format: Preprint
Published: 2024
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author Tuchinda, Nutth
Wagih, Malik
Schuh, Christopher A.
author_facet Tuchinda, Nutth
Wagih, Malik
Schuh, Christopher A.
contents At very fine grain sizes, grain boundary segregation can deviate from conventional behavior due to triple junction effects. While this issue has been addressed in prior work for substitutional alloys, here we develop a framework that accounts for interstitial sites in the grains, grain boundaries, and triple junctions of model Pd(H) polycrystals. This approach allows computation of interstitial segregation spectra separately at both defect types, which permits an understanding of segregation at all grain sizes via a size-scaling spectral isotherm. The size dependencies of dilute Pd(H) are found to be influenced not only by the triple junction content, but also by grain size-dependent lattice strains; the latter effect is evidenced by size dependencies of individual grain boundary and junction subspectra. The framework proposed here is applicable to interstitial alloys in general, and may serve as a basis for interfacial engineering in interstitial nanocrystalline alloys. As an example, we show using the dilute limit isotherm that hydrogen density can triple in nanocrystalline vis-à-vis microcrystalline Pd due to hydrogen adsorption at intergranular defect sites.
format Preprint
id arxiv_https___arxiv_org_abs_2411_18537
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Interstitial Solute Segregation at Triple Junctions: Implications for the Hydrogen Storage Properties of Nanomaterials
Tuchinda, Nutth
Wagih, Malik
Schuh, Christopher A.
Materials Science
At very fine grain sizes, grain boundary segregation can deviate from conventional behavior due to triple junction effects. While this issue has been addressed in prior work for substitutional alloys, here we develop a framework that accounts for interstitial sites in the grains, grain boundaries, and triple junctions of model Pd(H) polycrystals. This approach allows computation of interstitial segregation spectra separately at both defect types, which permits an understanding of segregation at all grain sizes via a size-scaling spectral isotherm. The size dependencies of dilute Pd(H) are found to be influenced not only by the triple junction content, but also by grain size-dependent lattice strains; the latter effect is evidenced by size dependencies of individual grain boundary and junction subspectra. The framework proposed here is applicable to interstitial alloys in general, and may serve as a basis for interfacial engineering in interstitial nanocrystalline alloys. As an example, we show using the dilute limit isotherm that hydrogen density can triple in nanocrystalline vis-à-vis microcrystalline Pd due to hydrogen adsorption at intergranular defect sites.
title Interstitial Solute Segregation at Triple Junctions: Implications for the Hydrogen Storage Properties of Nanomaterials
topic Materials Science
url https://arxiv.org/abs/2411.18537