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Over 95% of large-scale length uniformity in template-assisted electrodeposited nanowires by subzero-temperature electrodeposition.

Shin S, Kong BH, Kim BS, Kim KM, Cho HK, Cho HH - Nanoscale Res Lett (2011)

Bottom Line: Even with highly disordered commercial porous anodic aluminum oxide template and conventional potentiostatic electrodeposition, length uniformity over 95% can be achieved when the deposition temperature is lowered down to -2.4°C.Decreased diffusion coefficient and ion concentration gradient due to the lowered deposition temperature effectively reduces ion diffusion rate, thereby favors uniform nanowire growth.Moreover, by varying the deposition temperature, we show that also the pore nucleation and the crystallinity can be controlled.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Mechanical Engineering, Yonsei University, Seoul, 120-749, Korea. hhcho@yonsei.ac.kr.

ABSTRACT
In this work, we report highly uniform growth of template-assisted electrodeposited copper nanowires on a large area by lowering the deposition temperature down to subzero centigrade. Even with highly disordered commercial porous anodic aluminum oxide template and conventional potentiostatic electrodeposition, length uniformity over 95% can be achieved when the deposition temperature is lowered down to -2.4°C. Decreased diffusion coefficient and ion concentration gradient due to the lowered deposition temperature effectively reduces ion diffusion rate, thereby favors uniform nanowire growth. Moreover, by varying the deposition temperature, we show that also the pore nucleation and the crystallinity can be controlled.

No MeSH data available.


TEM images of the Cu nanowires at various deposition temperatures. (a) -1.5°C; (b) 60.5°C. Insets are the selected area electron diffraction patterns.
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Figure 5: TEM images of the Cu nanowires at various deposition temperatures. (a) -1.5°C; (b) 60.5°C. Insets are the selected area electron diffraction patterns.

Mentions: However, XRD results (Figure A2 in Additional file 1) showed that the overall grain orientation and the preferential growth direction were not significantly changed with deposition temperature. This is probably due to the fact that the electrodeposited nanowires are generally polycrystalline in nature, and XRD can only give the overall sum of multiple crystallographic orientations, which implies that without a significant enhancement of crystallinity (single crystalline), the diffraction patterns should not be varied much. The preferential growth direction of Cu nanowires was (111) throughout the whole temperature range. The TEM images of the Cu nanowires either from Figure 5a or 5b showed that a large number of spotty contrasts were observed with rough surface morphology regardless of the deposition temperature, which is typically observed in electrodeposited nanowires [33-36]. Obviously, this implies that the nanowires are in polycrystalline nature where the growth process is based on a typical 3D nucleation-coalescence mechanism [30,37]. However, the selected area electron diffraction patterns which are presented in the insets of Figure 5 showed an enhancement in the crystallinity with increasing deposition temperature where more enhanced diffraction spots were observed and the polycrystalline ring patterns were subsequently weakened. This directly indicates that the higher deposition temperature induces more favorable growth of existing grains that results in enhanced crystallinity, which is in conjuction with nucleation mechanism as mentioned earlier.


Over 95% of large-scale length uniformity in template-assisted electrodeposited nanowires by subzero-temperature electrodeposition.

Shin S, Kong BH, Kim BS, Kim KM, Cho HK, Cho HH - Nanoscale Res Lett (2011)

TEM images of the Cu nanowires at various deposition temperatures. (a) -1.5°C; (b) 60.5°C. Insets are the selected area electron diffraction patterns.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211979&req=5

Figure 5: TEM images of the Cu nanowires at various deposition temperatures. (a) -1.5°C; (b) 60.5°C. Insets are the selected area electron diffraction patterns.
Mentions: However, XRD results (Figure A2 in Additional file 1) showed that the overall grain orientation and the preferential growth direction were not significantly changed with deposition temperature. This is probably due to the fact that the electrodeposited nanowires are generally polycrystalline in nature, and XRD can only give the overall sum of multiple crystallographic orientations, which implies that without a significant enhancement of crystallinity (single crystalline), the diffraction patterns should not be varied much. The preferential growth direction of Cu nanowires was (111) throughout the whole temperature range. The TEM images of the Cu nanowires either from Figure 5a or 5b showed that a large number of spotty contrasts were observed with rough surface morphology regardless of the deposition temperature, which is typically observed in electrodeposited nanowires [33-36]. Obviously, this implies that the nanowires are in polycrystalline nature where the growth process is based on a typical 3D nucleation-coalescence mechanism [30,37]. However, the selected area electron diffraction patterns which are presented in the insets of Figure 5 showed an enhancement in the crystallinity with increasing deposition temperature where more enhanced diffraction spots were observed and the polycrystalline ring patterns were subsequently weakened. This directly indicates that the higher deposition temperature induces more favorable growth of existing grains that results in enhanced crystallinity, which is in conjuction with nucleation mechanism as mentioned earlier.

Bottom Line: Even with highly disordered commercial porous anodic aluminum oxide template and conventional potentiostatic electrodeposition, length uniformity over 95% can be achieved when the deposition temperature is lowered down to -2.4°C.Decreased diffusion coefficient and ion concentration gradient due to the lowered deposition temperature effectively reduces ion diffusion rate, thereby favors uniform nanowire growth.Moreover, by varying the deposition temperature, we show that also the pore nucleation and the crystallinity can be controlled.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Mechanical Engineering, Yonsei University, Seoul, 120-749, Korea. hhcho@yonsei.ac.kr.

ABSTRACT
In this work, we report highly uniform growth of template-assisted electrodeposited copper nanowires on a large area by lowering the deposition temperature down to subzero centigrade. Even with highly disordered commercial porous anodic aluminum oxide template and conventional potentiostatic electrodeposition, length uniformity over 95% can be achieved when the deposition temperature is lowered down to -2.4°C. Decreased diffusion coefficient and ion concentration gradient due to the lowered deposition temperature effectively reduces ion diffusion rate, thereby favors uniform nanowire growth. Moreover, by varying the deposition temperature, we show that also the pore nucleation and the crystallinity can be controlled.

No MeSH data available.