Hydrostatic Pressure Effects on the Structural and Electronic Properties of Carbon Nanotubes

Abstract

We study the structural and electronic properties of isolated single-wall carbon nanotubes (SWNTs) under hydrostatic pressure using a combination of theoretical techniques: Continuum elasticity models, classical molecular dynamics simulations, tight-binding electronic structure methods, and first-principles total energy calculations within the density-functional and pseudopotential frameworks. For pressures below a certain critical pressure $P_c$, the SWNTs' structure remains cylindrical and the Kohn-Sham energy gaps of semiconducting SWNTs have either positive or negative pressure coefficients depending on the value of $(n,m)$, with a distinct "family" (of the same $n-m$) behavior. The diameter and chirality dependence of the pressure coefficients can be described by a simple analytical expression. At $P_c$, molecular-dynamics simulations predict that isolated SWNTs undergo a pressure-induced symmetry-breaking transformation from a cylindrical shape to a collapsed geometry. This transition is described by a simple elastic model as arising from the competition between the bond-bending and $PV$ terms in the enthalpy. The good agreement between calculated and experimental values of $P_c$ provides a strong support to the ``collapse'' interpretation of the experimental transitions in bundles.

To appear in the Proceedings of the 11th International Conference on High Pressure Semiconductor Physics (invited paper)

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Cited by in corpus (7)

• Collapse of Double-Walled Carbon Nanotube Bundles under Hydrostatic Pressure
• Structural transformations of double-walled carbon nanotube bundle under hydrostatic pressure
• Infrared spectroscopic studies on unoriented single-walled carbon nanotube films under hydrostatic pressure
• Stabilization of carbon nanotubes by filling with inner tubes: An optical spectroscopy study on double-walled carbon nanotubes under hydrostatic pressure
• Energy barriers for collapsing large-diameter carbon nanotubes
• Strain, Anharmonicity and Finite-Size Effects on the Vibrational Properties of Linear Carbon Chains
• Carbon nanotubes collapse phase diagram with arbitrary number of walls. Collapse modes and macroscopic analog