title: Bulk synthesis, growth mechanism and properties of highly pure ultrafine boron nitride nanotubes with diameters of sub-10 nm.
abstract: As a structural analogue of the carbon nanotube (CNT), the boron nitride nanotube (BNNT) has become one of the most intriguing non-carbon nanostructures. However, up to now the pre-existing restrictions/limitations of BNNT syntheses have made the progress in their research rather modest. This work presents a new route toward the synthesis of highly pure ultrafine BNNTs based on a modified boron oxide (BO) CVD method. A new effective precursor--a mixture of Li₂O and B--has been proposed for the growth of thin, few-layer BNNTs in bulk amounts. The Li₂O utilized as the precursor plays the crucial role for the present nanotube growth. The prepared BNNTs have average external diameters of sub-10 nm and lengths of up to tens of µm. Electron energy loss spectrometry and Raman spectroscopy demonstrate the ultimate phase purity of the ultrafine BNNTs. Property studies indicate that the ultrafine nanotubes are perfect electrical insulators exhibiting superb resistance to oxidation and strong UV emission. Moreover, their reduced diameters lead to a dramatically decreased population of defects within the tube walls and result in the observation of near-band-edge (NBE) emission at room temperature.
authors.affiliation: International Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science, Namiki 1-1, Tsukuba, Ibaraki 305-0044, Japan. huangyang.nims@gmail.com
authors.forename: Yang
authors.initials: Y
authors.lastname: Huang
authors.forename: Jing
authors.initials: J
authors.lastname: Lin
authors.forename: Chengchun
authors.initials: C
authors.lastname: Tang
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Bando
authors.forename: Chunyi
authors.initials: C
authors.lastname: Zhi
authors.forename: Tianyou
authors.initials: T
authors.lastname: Zhai
authors.forename: Benjamin
authors.initials: B
authors.lastname: Dierre
authors.forename: Takashi
authors.initials: T
authors.lastname: Sekiguchi
authors.forename: Dmitri
authors.initials: D
authors.lastname: Golberg