scholarly journals Atomic Pathways of Solute Segregation in the Vicinity of Nanoscale Defects

Nano Letters ◽  
2021 ◽  
Author(s):  
Samik Mukherjee ◽  
Simone Assali ◽  
Oussama Moutanabbir
Keyword(s):  
Author(s):  
J. R. Michael ◽  
C. H. Lin ◽  
S. L. Sass

The segregation of solute atoms to grain boundaries in polycrystalline solids can be responsible for embrittlement of the grain boundaries. Although Auger electron spectroscopy (AES) and analytical electron microscopy (AEM) have verified the occurrence of solute segregation to grain boundaries, there has been little experimental evidence concerning the distribution of the solute within the plane of the interface. Sickafus and Sass showed that Au segregation causes a change in the primary dislocation structure of small angle [001] twist boundaries in Fe. The bicrystal specimens used in their work, which contain periodic arrays of dislocations to which Au is segregated, provide an excellent opportunity to study the distribution of Au within the boundary by AEM.The thin film Fe-0.8 at% Au bicrystals (composition determined by Rutherford backscattering spectroscopy), ∼60 nm thick, containing [001] twist boundaries were prepared as described previously. The bicrystals were analyzed in a Vacuum Generators HB-501 AEM with a field emission electron source and a Link Analytical windowless x-ray detector.


2021 ◽  
Vol 201 ◽  
pp. 113982
Author(s):  
Huan Zhang ◽  
Yangxin Li ◽  
Zhigang Ding ◽  
Tian Xie ◽  
Ruixue Liu ◽  
...  

2005 ◽  
Vol 903 ◽  
Author(s):  
Andrew Detor ◽  
Michael K. Miller ◽  
Christopher A. Schuh

AbstractAtom probe tomography is used to observe the solute distribution in electrodeposited nanocrystalline Ni-W alloys with three different grain sizes (3, 10, and 20 nm) and the results are compared with atomistic computer simulations. The presence of grain boundary segregation is confirmed by detailed analysis of composition fluctuations in both experimental and simulated structures, and its extent quantified by a frequency distribution analysis. In contrast to other nanocrystalline alloys, the present Ni-W alloys exhibit only a subtle amount of solute segregation to the intergranular regions. This finding is consistent with quantitative predictions for these alloys based upon a thermodynamic model of grain boundary segregation.


2002 ◽  
Vol 751 ◽  
Author(s):  
Qinglei Wang ◽  
Guoda D. Lian ◽  
Elizabeth C. Dickey

ABSTRACTSolute segregation to grain boundaries is a fundamental phenomenon in polycrystalline metal-oxide electroceramics that has enormous implications for the macroscopic dielectric behavior of the materials. This paper presents a systematic study of solute segregation in a model dielectric, titanium dioxide. We investigate the relative role of the electrostatic versus strain energy driving forces for segregation by studying yttrium-doped specimens. Through analytical transmission electron microscopy studies, we quantitatively determine the segregation behavior of the material. The measured Gibbsian interfacial excesses are compared to thermodynamic predictions.


2020 ◽  
Vol 4 (7) ◽  
Author(s):  
G. D. Samolyuk ◽  
M. Eisenbach ◽  
D. Shin ◽  
Y. N. Osetsky ◽  
A. Shyam ◽  
...  

1981 ◽  
Vol 4 ◽  
Author(s):  
J. Narayan ◽  
G. L. Olson ◽  
O. W. Holland

ABSTRACTTime-resolved-reflectivity measurements have been combined with transmission electron microscopy (cross-section and plan-view), Rutherford backscattering and ion channeling techniques to study the details of laser induced solid phase epitaxial growth in In+ and Sb+ implanted silicon in the temperature range from 725 to 1500 °K. The details of microstructures including the formation of polycrystals, precipitates, and dislocations have been correlated with the dynamics of crystallization. There were limits to the dopant concentrations which could be incorporated into substitutional lattice sites; these concentrations exceeded retrograde solubility limits by factors up to 70 in the case of the Si-In system. The coarsening of dislocation loops and the formation of a/2<110>, 90° dislocations in the underlying dislocation-loop bands are described as a function of laser power.


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