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Tuning the electronic properties of boron nitride nanotube by mechanical uni-axial deformation: a DFT study.

Ju SP, Wang YC, Lien TW - Nanoscale Res Lett (2011)

Bottom Line: The effect of uni-axial strain on the electronic properties of (8,0) zigzag and (5,5) armchair boron nitride nanotubes (BNNT) is addressed by density functional theory calculation.The stress-strain profiles indicate that these two BNNTS of differing types display very similar mechanical properties, but there are variations in HOMO-LUMO gaps at different strains, indicating that the electronic properties of BNNTs not only depend on uni-axial strain, but on BNNT type.The variations in nanotube geometries, partial density of states of B and N atoms, B and N charges are also discussed for (8,0) and (5,5) BNNTs at different strains.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Mechanical and Electro-Mechanical Engineering, Center for Nanoscience and Nanotechnology, National Sun Yat-sen University, Kaohsiung, 804, Taiwan. jushin-pon@mail.nsysu.edu.tw.

ABSTRACT
The effect of uni-axial strain on the electronic properties of (8,0) zigzag and (5,5) armchair boron nitride nanotubes (BNNT) is addressed by density functional theory calculation. The stress-strain profiles indicate that these two BNNTS of differing types display very similar mechanical properties, but there are variations in HOMO-LUMO gaps at different strains, indicating that the electronic properties of BNNTs not only depend on uni-axial strain, but on BNNT type. The variations in nanotube geometries, partial density of states of B and N atoms, B and N charges are also discussed for (8,0) and (5,5) BNNTs at different strains.

No MeSH data available.


Related in: MedlinePlus

Simulation model and definitions for (a) bond angles and bond lengths of (5,5) BNNT are shown. Bonds normal to axial are shown as Bond-III, and other ones slanted to the axial are shown as Bond-IV. Bond angles are labeled as E, F, G, and H. Variation of (b) the radial buckling and bond lengths of (5,5) BNNT at different strains and (c) the radial buckling and bond angles of (5,5) BNNT at different strains.
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Figure 4: Simulation model and definitions for (a) bond angles and bond lengths of (5,5) BNNT are shown. Bonds normal to axial are shown as Bond-III, and other ones slanted to the axial are shown as Bond-IV. Bond angles are labeled as E, F, G, and H. Variation of (b) the radial buckling and bond lengths of (5,5) BNNT at different strains and (c) the radial buckling and bond angles of (5,5) BNNT at different strains.

Mentions: The relationship of bond lengths and bending angles of (5,5) BNNT at different strains are shown in Figure 4b,c, with the corresponding bond lengths and bending angles depicted in Figure 4a. The B-N bonds normal to the axial direction are designated as Bond-III, and those slanted from the axial direction are labeled as Bond-IV. According to the bending angles formed by different bond types and central atom type, four angles labeled as E, F, G, and H are used to indicate different bending angle types in Figure 4c. In Figure 4b, the lengths of Bond-IV significantly increase with the increase of strain, but the lengths of Bond-III remain constant when the strain is smaller than 5% and slightly decrease when the strain is larger than 5%. As shown in Figure 4c, angles F and G increase when the strain increases, whereas decreases in angles E and H with the increase of strain can also be seen. Consequently, the elongation of the (5,5) armchair BNNT is mainly due to the altering of bond angles and the elongation of Bond-IV which is slanted from the axial direction.


Tuning the electronic properties of boron nitride nanotube by mechanical uni-axial deformation: a DFT study.

Ju SP, Wang YC, Lien TW - Nanoscale Res Lett (2011)

Simulation model and definitions for (a) bond angles and bond lengths of (5,5) BNNT are shown. Bonds normal to axial are shown as Bond-III, and other ones slanted to the axial are shown as Bond-IV. Bond angles are labeled as E, F, G, and H. Variation of (b) the radial buckling and bond lengths of (5,5) BNNT at different strains and (c) the radial buckling and bond angles of (5,5) BNNT at different strains.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211212&req=5

Figure 4: Simulation model and definitions for (a) bond angles and bond lengths of (5,5) BNNT are shown. Bonds normal to axial are shown as Bond-III, and other ones slanted to the axial are shown as Bond-IV. Bond angles are labeled as E, F, G, and H. Variation of (b) the radial buckling and bond lengths of (5,5) BNNT at different strains and (c) the radial buckling and bond angles of (5,5) BNNT at different strains.
Mentions: The relationship of bond lengths and bending angles of (5,5) BNNT at different strains are shown in Figure 4b,c, with the corresponding bond lengths and bending angles depicted in Figure 4a. The B-N bonds normal to the axial direction are designated as Bond-III, and those slanted from the axial direction are labeled as Bond-IV. According to the bending angles formed by different bond types and central atom type, four angles labeled as E, F, G, and H are used to indicate different bending angle types in Figure 4c. In Figure 4b, the lengths of Bond-IV significantly increase with the increase of strain, but the lengths of Bond-III remain constant when the strain is smaller than 5% and slightly decrease when the strain is larger than 5%. As shown in Figure 4c, angles F and G increase when the strain increases, whereas decreases in angles E and H with the increase of strain can also be seen. Consequently, the elongation of the (5,5) armchair BNNT is mainly due to the altering of bond angles and the elongation of Bond-IV which is slanted from the axial direction.

Bottom Line: The effect of uni-axial strain on the electronic properties of (8,0) zigzag and (5,5) armchair boron nitride nanotubes (BNNT) is addressed by density functional theory calculation.The stress-strain profiles indicate that these two BNNTS of differing types display very similar mechanical properties, but there are variations in HOMO-LUMO gaps at different strains, indicating that the electronic properties of BNNTs not only depend on uni-axial strain, but on BNNT type.The variations in nanotube geometries, partial density of states of B and N atoms, B and N charges are also discussed for (8,0) and (5,5) BNNTs at different strains.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Mechanical and Electro-Mechanical Engineering, Center for Nanoscience and Nanotechnology, National Sun Yat-sen University, Kaohsiung, 804, Taiwan. jushin-pon@mail.nsysu.edu.tw.

ABSTRACT
The effect of uni-axial strain on the electronic properties of (8,0) zigzag and (5,5) armchair boron nitride nanotubes (BNNT) is addressed by density functional theory calculation. The stress-strain profiles indicate that these two BNNTS of differing types display very similar mechanical properties, but there are variations in HOMO-LUMO gaps at different strains, indicating that the electronic properties of BNNTs not only depend on uni-axial strain, but on BNNT type. The variations in nanotube geometries, partial density of states of B and N atoms, B and N charges are also discussed for (8,0) and (5,5) BNNTs at different strains.

No MeSH data available.


Related in: MedlinePlus