Kang Hong Seok
College of Liberal Arts, Jeonju University, Hyoja-dong, Wansan-ku, Chonju, Chonbuk 560-759, Republic of Korea.
J Phys Chem B. 2006 Mar 16;110(10):4621-8. doi: 10.1021/jp056941l.
On the basis of calculations using the density functional theory, it is shown that BNNT synthesis could produce tubes deprived of one (B1 hole) or two (B2 hole) boron atoms under the condition where nitrogen atoms exist in excess throughout this study. The relative populations of various isomers of defective tubes will depend on the chirality of the tube. Interestingly, calculations show that B2 holes are much more favored than B1 holes, particularly in armchair tubes. Electronic properties are modified in such a way that the band gap is decreased through the introduction of defect states inside the gap. Magnetic properties will also be dependent on the chirality. The majority of armchair tubes with B2 holes will be nonmagnetic, while the majority of zigzag tubes with defects will exhibit magnetism. Contrary to the case of defect-free BNNT, the defective tubes are expected to be easily subject to reduction by accommodating excess electrons in the presence of Li atoms. In addition, the defect sites will show a higher affinity toward hydrogenation than the defect-free sites.
基于使用密度泛函理论的计算结果表明，在本研究中氮原子始终过量的条件下，氮化硼纳米管（BNNT）的合成可能会产生缺少一个硼原子（B1孔）或两个硼原子（B2孔）的管子。缺陷管的各种异构体的相对丰度将取决于管子的手性。有趣的是，计算表明B2孔比B1孔更受青睐，特别是在扶手椅型管子中。电子性质以这样一种方式改变，即通过在带隙内引入缺陷态使带隙减小。磁性也将取决于手性。大多数具有B2孔的扶手椅型管子将是非磁性的，而大多数有缺陷的锯齿型管子将表现出磁性。与无缺陷的BNNT情况相反，有缺陷的管子预计在有锂原子存在的情况下通过容纳过量电子而容易被还原。此外，缺陷位点对氢化的亲和力将高于无缺陷位点。
