arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv 0907.2366cond-mat.mtrl-sci
收藏

氢在石墨烯上的振动特性和扩散

Vibrational properties and diffusion of hydrogen on graphene

Carlos P. Herrero, Rafael Ramirez

摘要:

采用路径积分分子动力学模拟研究了氢和氘在单层石墨烯上的化学吸附。在200至1500 K的范围内,通过使用紧束缚势拟合密度泛函计算,这些点缺陷的熔点温度特性进行了分析。一方面,吸附原子的振动性质研究在其平衡位置,连接到C原子。振动显示出明显的非谐性,来自动能和势能之间的比较,以及氢和氘的振动能之间的比较。另一方面,用量子过渡态理论研究了吸附原子的运动。在室温下,发现量子效应将石墨烯片上的氢扩散率提高了20倍。

英文摘要:

Hydrogen and deuterium chemisorption on a single layer of graphene has been studied by path-integral molecular dynamics simulations. Finite-temperature properties of these point defects were analyzed in the range from 200 to 1500 K, by using a tight-binding potential fitted to density-functional calculations. On one side, vibrational properties of the adatoms are studied at their equilibrium positions, linked to C atoms. The vibrations display an appreciable anharmonicity, as derived from comparison between kinetic and potential energy, as well as between vibrational energy for hydrogen and deuterium. On the other side, adatom motion has been studied by quantum transition-state theory. At room temperature, quantum effects are found to enhance the hydrogen diffusivity on the graphene sheet by a factor of 20.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑