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Báo cáo hóa học: " Tuning the electronic properties of boron nitride nanotube by mechanical uni-axial deformation: a DFT study"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Tuning the electronic properties of boron nitride nanotube by mechanical uni-axial deformation: a DFT study | Ju et al. Nanoscale Research Letters 2011 6 160 http www.nanoscalereslett.eom content 6 1 160 o Nanoscale Research Letters a SpringerOpen Journal NANO EXPRESS Open Access Tuning the electronic properties of boron nitride nanotube by mechanical uni-axial deformation a DFT study Shin-Pon Ju Yao-Chun Wang Ting-Wei Lien 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. Introduction In nanoscale materials especially for nanotubes numerous special properties depend on their ultra-small sizes. Carbon nanotubes CNTs discovered by Iijima in 1991 1 have been a very promising one-dimensional material in nanoscience. Theoretical calculations and experimental measurements on carbon nanotubes have shown many exceptional properties that make CNTs promising for several proposed applications such as high Young s modulus and electronic properties 1-6 . Boron nitride nanotubes BNNTs were theoretically predicted in 1994 and were synthesized experimentally in the following year 7 . BNNTs are a structural analogy to CNTs that instead alternate boron and nitride atoms to replace the carbon atoms in the hexagonal structure. Although CNTs and BNNTs have similar structures their properties are quite different. For example electronic properties of CNT are distinctly different from those of BNNTs because of the large ionicity of B-N bonds 2 . Another difference is that BNNTs have a much better resistance to oxidation in .