氮化硼纳米管的显微表征及其高分辨成像研究

采用化学气相沉积法制备了多壁氮化硼纳米管（BNNT）,高分辨电镜研究表明,BNNT一个重要的结构特征为层间有序堆垛,且大多以菱面体（r-BN）方式堆垛;多数BNNT具有择优生长取向,管轴沿BN六角网格平面的[1010]方向,即多数BNNT为锯齿型.基于其显微结构特征建立了多壁BNNT的结构模型,并通过计算机模拟其高分辨成像特点,发现r-BN堆垛的BNNT的HRTEM成像效果对其直径、层数以及观察视角等参数敏感,提出也可以通过管身高分辨像出现水纹状条纹直接判别r-BN堆垛.

MICROSCOPIC CHARACTERIZATION AND HRTEM IMAGES OF BORON NITRIDE NANOTUBES

Multi-walled boron nitride nanotubes (BNNTs) synthesized by chemical vapor deposition were revealed to possess a definite stacking order (dominant r-BN stacking) and preferential zigzag chirality. Based on the microscopic characters of BNNTs, structure models were built and computer simulations of HRTEM images were carried out. It was found that HRTEM images of BNNTs with r-BN stacking are sensitive to the wall number, tubes diameter and angle of observations. Appearance of moire fringe on the HRTEM image of tube body was proposed to judge the existance of r-BN stacking.