In Situ Electron Microscopy Investigation of Physical Properties of Multiwalled Carbon Nanotubes

9971412 De Heer多壁碳纳米管的电子和机械性能已被广泛研究，但仍然知之甚少。在这项研究中，这些问题的攻击通过一系列的原位电子显微镜实验中，个别的，以及表征纳米管的性能进行测量。 这些性质包括电子输运、场发射、带电纳米管的静电势和弹性常数。 这种测量的可行性已经通过一系列的初步实验证明，其中包括：（i）涉及纳米管的电接触的制造和断开;（ii）原位场发射;（iii）带电纳米管的相位差效应;和（iv）电诱导机械共振的观察。 后一种效应表明了纳米力学的新方法。 这项研究为研究生和博士后研究助理的培训提供了许多机会，该领域处于当代凝聚态物理学和材料科学的最前沿。碳纳米管是几乎完美的石墨管，具有显着的性能，其中包括其卓越的机械强度，高载流能力，可能的储氢能力等。 为了表征这些性质并发现新的性质，必须单独研究碳管。主要研究者已开发出此类研究所需的方法。 这项研究为在21世纪提供许多就业机会的先进技术领域培养研究生和博士后研究人员提供了机会。

9971412De HeerElectronic and mechanical properties of multi-walled carbon nanotubes have been widely investigated but are still only poorly understood. In this research these problems are attacked by means of a series of in situ electron microscopy experiments in which the properties of individual, well characterized nanotubes are measured. These properties include the electronic transport, field emission, electrostatic potentials of the electrically charged nanotubes, and elastic constants. The feasibility of such measurements have been demonstrated by a series of preliminary experiments which include (i) the making and breaking of electrical contacts involving nanotubes; (ii) in situ field emission; (iii) phase contrast effects of the charged nanotubes; and (iv) observations of electrically induced mechanical resonances. The latter effect suggests a new approach towards nanomechanics. This research offers many opportunities for the training of graduate students and postdoctoral research associates in a field which stands at the forefront of contemporary condensed matter physics and materials sciences.%%%Carbon nanotubes are nearly perfect graphitic tubes with remarkable properties among which are their exceptional mechanical strength, high current carrying capabilities, possible hydrogen storage capabilities, and others. In order to characterize these properties and to discover new ones it is essential that carbon tubes be studied individually. The principal investigator has developed the required methods for such studies. This research offers opportunities for the training of graduate students and postdoctoral research associates in an advanced technological field that offers many employment opportunities during the 21st Century.***