TY - JOUR T1 - MD Simulation of Structural and Mechanical Transformation of Single-Walled Carbon Nanotubes Under Pressure AU - J. Zang, O. Aldás-Palacios & F. Liu JO - Communications in Computational Physics VL - 3 SP - 451 EP - 465 PY - 2007 DA - 2007/02 SN - 2 DO - http://doi.org/ UR - https://global-sci.org/intro/article_detail/cicp/7912.html KW - Carbon nanotube, high-pressure solid-state phase transformation, MD simulation. AB -

We investigate the structural and mechanical properties of single-walled carbon nanotubes (SWNTs) under hydrostatic pressure, using constant-pressure molecular dynamics (MD) simulations. We observed that all the SWNTs, independent of their size and chirality, behave like a classical elastic ring exhibiting a buckling transition transforming their cross-sectional shape from a circle to an ellipse. The simulated critical transition pressure agrees well with the prediction from continuum mechanics theory, even for the smallest SWNT with a radius of 0.4nm. Accompanying the buckling shape transition, there is a mechanical hardness transition, upon which the radial moduli of the SWNTs decrease by two orders of magnitude. Further increase of pressure will eventually lead to a second transition from an elliptical to a peanut shape. The ratio of the second shape transition pressure over the first one is found to be very close to a constant of ∼1.2, independent of the tube size and chirality.