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Hetero-twin formation during growth of nano-scale Al-TiN composites - experimental and DFT studies
Abstract
It is well known that high stacking fault energy metals such as Al do not form either growth twins or mechanical twins easily. Although mechanical twins in nanocrystalline Al have been observed under certain conditions, growth twins have never been observed. In this work, the authors report for the first time, through transmission electron microscopy (TEM), that Al layers, when deposited on TiN layers, tend to grow in a twin relationship to both the TiN layer and the underlying Al layer. The TiN layers assume the orientation of the Al layers below. Calculations using density functional theory (DFT) show that nitrogen termination in the {l_brace}111{r_brace} growth plane of the TiN layers favors the growth of twin oriented Al layers over these TiN layers. This finding provides a way to create a twin-modulated structure in Al with the inclusion of intermediate nm-scale layer of an ionic solid such as TiN. Al metal is resistant to twinning, as it has a high stacking fault energy (SFE) of > 150 mJ/m. Although twins have been observed in nano-scale grains of Al, and predicted by molecular dynamics (MD) simulations in conditions when the nanoscale grains are plastically deformed, no process or phenomenon has beenmore »
- Authors:
-
- Los Alamos National Laboratory
- MSE, OSU
- Publication Date:
- Research Org.:
- Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
- Sponsoring Org.:
- USDOE
- OSTI Identifier:
- 971321
- Report Number(s):
- LA-UR-09-06250; LA-UR-09-6250
Journal ID: ISSN 0031-9007; PRLTAO; TRN: US201004%%83
- DOE Contract Number:
- AC52-06NA25396
- Resource Type:
- Journal Article
- Journal Name:
- Physical Review Letters
- Additional Journal Information:
- Journal Name: Physical Review Letters; Journal ID: ISSN 0031-9007
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 36 MATERIALS SCIENCE; DEPOSITION; DIFFUSION BARRIERS; FUNCTIONALS; MECHANICAL PROPERTIES; NITROGEN; ORIENTATION; STACKING FAULTS; TRANSMISSION ELECTRON MICROSCOPY; TWINNING
Citation Formats
Bhattacharyya, Dhriti, Liu, Xiang - Yang, Hoagland, Richard G, Misra, Amit, Genc, A, and Fraser, H L. Hetero-twin formation during growth of nano-scale Al-TiN composites - experimental and DFT studies. United States: N. p., 2009.
Web.
Bhattacharyya, Dhriti, Liu, Xiang - Yang, Hoagland, Richard G, Misra, Amit, Genc, A, & Fraser, H L. Hetero-twin formation during growth of nano-scale Al-TiN composites - experimental and DFT studies. United States.
Bhattacharyya, Dhriti, Liu, Xiang - Yang, Hoagland, Richard G, Misra, Amit, Genc, A, and Fraser, H L. 2009.
"Hetero-twin formation during growth of nano-scale Al-TiN composites - experimental and DFT studies". United States. https://www.osti.gov/servlets/purl/971321.
@article{osti_971321,
title = {Hetero-twin formation during growth of nano-scale Al-TiN composites - experimental and DFT studies},
author = {Bhattacharyya, Dhriti and Liu, Xiang - Yang and Hoagland, Richard G and Misra, Amit and Genc, A and Fraser, H L},
abstractNote = {It is well known that high stacking fault energy metals such as Al do not form either growth twins or mechanical twins easily. Although mechanical twins in nanocrystalline Al have been observed under certain conditions, growth twins have never been observed. In this work, the authors report for the first time, through transmission electron microscopy (TEM), that Al layers, when deposited on TiN layers, tend to grow in a twin relationship to both the TiN layer and the underlying Al layer. The TiN layers assume the orientation of the Al layers below. Calculations using density functional theory (DFT) show that nitrogen termination in the {l_brace}111{r_brace} growth plane of the TiN layers favors the growth of twin oriented Al layers over these TiN layers. This finding provides a way to create a twin-modulated structure in Al with the inclusion of intermediate nm-scale layer of an ionic solid such as TiN. Al metal is resistant to twinning, as it has a high stacking fault energy (SFE) of > 150 mJ/m. Although twins have been observed in nano-scale grains of Al, and predicted by molecular dynamics (MD) simulations in conditions when the nanoscale grains are plastically deformed, no process or phenomenon has been reported yet in which the deposition of an intermediate layer of a different material phase causes the subsequent layer of Al to be deposited in the twin orientation. The authors show in this paper that it is possible to form Al layers in twin orientation to each other across polar TiN layers, if these are grown so that both the Al and TiN layers have a {l_brace}111{r_brace} surface as their growth front. Since the deposition of Al and TiN layers is used in the formation of diffusion barriers, and the mechanical properties of these nanoscale multilayers are also seen to be exceptional, it is important to investigate and understand their structure at the nanometer length scale, and thence to be able to control it. Moreover, these findings point out a method of introducing nano-scale twins in high SFE materials in general, and can potentially improve the properties of nano-layered materials.},
doi = {},
url = {https://www.osti.gov/biblio/971321},
journal = {Physical Review Letters},
issn = {0031-9007},
number = ,
volume = ,
place = {United States},
year = {Thu Jan 01 00:00:00 EST 2009},
month = {Thu Jan 01 00:00:00 EST 2009}
}
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