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ZnSe nanotrenches: formation mechanism and its role as a 1D template.

Wang G, Lok SK, Sou IK - Nanoscale Res Lett (2011)

Bottom Line: High-resolution transmission electron microscopy was used to characterize the microstructures of ZnSe nanotrenches induced by mobile Au-alloy droplets.The contact side interfaces between the AuZnδ alloy droplets and the ZnSe as well as the four side walls of the resulting <011>-oriented nanotrenches were found all belong to the {111} plane family, with the front and back walls being the {111}A planes while the other two side walls being the {111}B planes.These findings offer a deeper understanding on the formation mechanism of the nanotrenches.

View Article: PubMed Central - HTML - PubMed

Affiliation: Nano Science and Technology Program, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China. phiksou@ust.hk.

ABSTRACT
High-resolution transmission electron microscopy was used to characterize the microstructures of ZnSe nanotrenches induced by mobile Au-alloy droplets. The contact side interfaces between the AuZnδ alloy droplets and the ZnSe as well as the four side walls of the resulting <011>-oriented nanotrenches were found all belong to the {111} plane family, with the front and back walls being the {111}A planes while the other two side walls being the {111}B planes. These findings offer a deeper understanding on the formation mechanism of the nanotrenches. Pure Au nanodashes were formed upon further deposition of Au on the nanotrenches.PACS: 61.46.Df, Structure of nanocrystals and nanoparticles. 81.16.Rf, Micro and nanoscale pattern formation. 68.37.Og, High resolution transmission electron microscopy.

No MeSH data available.


Tilted-view schematic diagrams of ZnSe lattice: (a) along [011] and (b) along  direction.
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Figure 3: Tilted-view schematic diagrams of ZnSe lattice: (a) along [011] and (b) along direction.

Mentions: In our previously published article, we have discussed the reason for the nanotrenches induced by the migration of AuZnδ being only oriented along a specific pair of <011> direction although there are four <011> directions on the surface of a (100)-oriented substrate of zinc-blended structure [16]. This is because the [011]/ and the pairs are not identical because of the inversion symmetry on the (100) plane of a zinc-blended structure. As viewed along the [011] and directions, the zigzag atomic chains presented on the viewing planes are in fact 180° off with regard to the location of the Zn and Se atoms, with Zn atoms at the top as viewed along the [011] direction while Se atoms at the top as viewed along the direction. We further argue that AuZnδ droplets prefer to attack Zn atoms more than Se atoms because it is more energetically favorable because the heat of formation of Au-Zn (-0.27 eV/atom) [19] is lower than that of Au-Se (-0.15 eV/atom) [20]. This study further reveals that the contact interfaces between the AuZnδ droplet and the ZnSe lattice are {111}A and {111}B planes for the [011]/ and the pairs, respectively, which in fact provides further evidence in support of our explanation described above. Figure 3a, b displays the tilted views of a ZnSe lattice as viewed along the [011] and directions, with the top surface terminated at (111)A and B, respectively. These schematic drawings are applicable to the views along the and directions as well. The inclined top surfaces represent the direct contact surface between a AuZnδ droplet and the ZnSe lattice. As can be seen in Figure 3, the contact surfaces for the [011]/ directions are Zinc terminated, while those for the directions are Se terminated. Being attributed to the difference between the heat of formation of Au-Zn and Au-Se, the [011]/ directions represent the preferred directions for the formation of the ZnSe nanotrenches since the migration of the AuZnδ droplets and their catalytic decomposition reaction are more favorable along these anti-parallel directions than along the directions.


ZnSe nanotrenches: formation mechanism and its role as a 1D template.

Wang G, Lok SK, Sou IK - Nanoscale Res Lett (2011)

Tilted-view schematic diagrams of ZnSe lattice: (a) along [011] and (b) along  direction.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211336&req=5

Figure 3: Tilted-view schematic diagrams of ZnSe lattice: (a) along [011] and (b) along direction.
Mentions: In our previously published article, we have discussed the reason for the nanotrenches induced by the migration of AuZnδ being only oriented along a specific pair of <011> direction although there are four <011> directions on the surface of a (100)-oriented substrate of zinc-blended structure [16]. This is because the [011]/ and the pairs are not identical because of the inversion symmetry on the (100) plane of a zinc-blended structure. As viewed along the [011] and directions, the zigzag atomic chains presented on the viewing planes are in fact 180° off with regard to the location of the Zn and Se atoms, with Zn atoms at the top as viewed along the [011] direction while Se atoms at the top as viewed along the direction. We further argue that AuZnδ droplets prefer to attack Zn atoms more than Se atoms because it is more energetically favorable because the heat of formation of Au-Zn (-0.27 eV/atom) [19] is lower than that of Au-Se (-0.15 eV/atom) [20]. This study further reveals that the contact interfaces between the AuZnδ droplet and the ZnSe lattice are {111}A and {111}B planes for the [011]/ and the pairs, respectively, which in fact provides further evidence in support of our explanation described above. Figure 3a, b displays the tilted views of a ZnSe lattice as viewed along the [011] and directions, with the top surface terminated at (111)A and B, respectively. These schematic drawings are applicable to the views along the and directions as well. The inclined top surfaces represent the direct contact surface between a AuZnδ droplet and the ZnSe lattice. As can be seen in Figure 3, the contact surfaces for the [011]/ directions are Zinc terminated, while those for the directions are Se terminated. Being attributed to the difference between the heat of formation of Au-Zn and Au-Se, the [011]/ directions represent the preferred directions for the formation of the ZnSe nanotrenches since the migration of the AuZnδ droplets and their catalytic decomposition reaction are more favorable along these anti-parallel directions than along the directions.

Bottom Line: High-resolution transmission electron microscopy was used to characterize the microstructures of ZnSe nanotrenches induced by mobile Au-alloy droplets.The contact side interfaces between the AuZnδ alloy droplets and the ZnSe as well as the four side walls of the resulting <011>-oriented nanotrenches were found all belong to the {111} plane family, with the front and back walls being the {111}A planes while the other two side walls being the {111}B planes.These findings offer a deeper understanding on the formation mechanism of the nanotrenches.

View Article: PubMed Central - HTML - PubMed

Affiliation: Nano Science and Technology Program, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China. phiksou@ust.hk.

ABSTRACT
High-resolution transmission electron microscopy was used to characterize the microstructures of ZnSe nanotrenches induced by mobile Au-alloy droplets. The contact side interfaces between the AuZnδ alloy droplets and the ZnSe as well as the four side walls of the resulting <011>-oriented nanotrenches were found all belong to the {111} plane family, with the front and back walls being the {111}A planes while the other two side walls being the {111}B planes. These findings offer a deeper understanding on the formation mechanism of the nanotrenches. Pure Au nanodashes were formed upon further deposition of Au on the nanotrenches.PACS: 61.46.Df, Structure of nanocrystals and nanoparticles. 81.16.Rf, Micro and nanoscale pattern formation. 68.37.Og, High resolution transmission electron microscopy.

No MeSH data available.