Hydrostatic pressure effects on the structural and electronicproperties of carbon nanotubes

Journal Article · Mon Mar 15 04:00:00 EST 2004 · Physica Status Solidi (b)

DOI:https://doi.org/10.1002/pssb.200405253· OSTI ID:919746

Capaz, Rodrigo B; Spataru, Catalin D; Tangney, Paul; Cohen, Marvin L; Louie, Steven G

We study the structural and electronic properties ofisolated single-wall carbon nanotubes (SWNTs) under hydrostatic pressureusing a combination of theoretical techniques: continuum elasticitymodels, classical molecular dynamics simulations, tight-bindingelectronic structure methods, and first-principles total energycalculations within the density-functional and pseudopotentialframeworks. For pressures below a certain critica pressure Pc, the SWNTs'structure remains cylindrical and the Kohn-Sham energy gaps ofsemiconducting SWNTs have either positive or negative pressurecoefficients depending on the value of (n,m) with a distinct "family" (ofthe same n-m) behavior. The diameter and chirality dependence of thepressure coefficients can be described by a simple analytical expression.At Pc, molecular-dynamics simulations predict that isolated SWNTs undergoa pressure-induced symmetry-breaking transformation from a cylindricalshape to a collapsed geometry. This transition is described by a simpleelastic model as arising from the competition between the bond-bendingand PV terms in the enthalpy. The good agreement between calculated andexperimental values of Pc provides a strong support to the "collapse"interpretation of the experimental transitions in bundles.

• Research Organization: Ernest Orlando Lawrence Berkeley NationalLaboratory, Berkeley, CA (US)
• Sponsoring Organization: USDOE Director. Office of Science. Basic EnergySciences
• DOE Contract Number: AC02-05CH11231
• OSTI ID: 919746
• Report Number(s): LBNL--59688; BnR: KC0301020
• Journal Information: Physica Status Solidi (b), Journal Name: Physica Status Solidi (b) Vol. 241; ISSN PSSBBD; ISSN 0370-1972
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
CARBON
CRITICAL PRESSURE
ELECTRONIC STRUCTURE
ENERGY GAP
HYDROSTATICS
NANOTUBES
PRESSURE COEFFICIENT
PRESSURE DEPENDENCE
SYMMETRY BREAKING