碳纳米管和硼纳米管热膨胀性能的第一性原理研究

摘要

采用密度泛函及分子动力学理论,对碳纳米管和硼纳米管的热膨胀性能进行了研究.研究发现小管径的硼纳来管具有出较好的反膨胀性能,硼纳米管的反膨胀性能与管径的关系和碳管的结果不同.低温下,硼六边形中心的硼原子的横向振动模式可能是其反膨胀性能的主要原因.小管径的硼纳米管的反膨胀性能可以和碳纳米管的性能相比较,表明小管径的硼纳米管在反膨胀领域具有很高的应用前景.%The thermal expansion characteristics of carbon nanotubes and boron nanotubes were investigated by density functional theory calculations and molecular dynamics simulations. It was found that boron nanotubes showed significant negative thermal expansion at small diameters.The variation of thermal expansion coefficient of the boron nanotubes with the tube diameter was very different from that of the carbon nanotubes. The obvious transverse vibration mode of the boron atoms in the center of boron hexagon at low temperature may be responsible for the negative thermal effect of the boron nanotubes. The negative thermal expansion coefficient of the small diameter boron nanotube was comparable to that of the carbon nanotube, which opened the potential applications of boron nanotubes as negative thermal expansion materials.