PHONON PROPERTIES OF BORON NITRIDE NANOSHEET

The exceptional properties of Boron Nitrides (BN) nanotube have attracted the attention of the researchers in past few years. BN nanotubes can be considered as insulating materialand are highly resistive to oxidation. In air BN nanotubes are stable up to at least 700˚C while highly crystalline and low defective BN nanotubes show stability up to 900˚C. High density nano electronic devices demands a nano material with good thermal conductivityand BN nanotube is among the best options as its thermal conductivity is high. BN nanotube show lot of other excellent properties like non cytotoxicity and ability of stable interaction with bio molecules make it more suitable for biological applications. The BN nanotubes have received considerable attraction on account of their unusual properties, which differ significantly from bulk counterpart. The possibilities for technological applications of BN nanotubes have motivated the researchers for study of properties and applications of these nanotubes. Therefore, these properties must be evaluated accurately and comprehensively to predict the possible behavior and potential of BN nanotubes for device applications. In crystalline materials, the scattering of mobile charge carriers occurs due to the fluctuating potential arising from lattice vibrations. Physically these lattice vibrations are attributed to the phonons, which signify the importance of phonon calculation. The crystal structure and inter-atomic interactions are also well described by phonon spectrum. The calculations for phonon spectrum of BN nanotubes are yet to explore completely. Furthermore, these calculations lead to investigate other physical properties like entropy, specific heat capacity, Debye temperature and so on.The BN nanotube is basically a cylindrical structure formed by rolling h-BN sheet and it can be classified into two categories chiral nanotube and achiral nanotube depending upon chiral angle. The achiral nanotube can be further classified as zigzag nanotube and armchair nanotube. The understanding of the dynamical properties of h-BN sheet is necessary. Therefore, in this work a short range force constant model has been used to study the phonons in sheet of zigzag BN nanotube by considering the interatomic interactions up to 2ndnearest neighbor. The calculated results are compared and analyzed with available results