Search for content and authors
 

Atomistic simulations of nanocomposite carbon films

Pantelis C. Kelires 

University of Crete (UOC), Vasilika Vouton, P.O. Box 2208, Heraklion 71003, Greece

Abstract

Nanocomposite carbon (n-C) films may be described as hybrid materials, consisting of C nanostructures embedded in a host amorphous carbon (a-C) matrix. This form of C offers the unique possibility to intermingle the properties of C nanostructures with those of pure a-C, and thus tailor the mechanical and electronic properties by controlling the type and size of the embedded structures and the hybrid state of the a-C matrix.

Here, I review recent computational work in my group aiming at an accurate atomistic description of n-C films. The methods employed are state-of-the-art Monte Carlo and tight-binding molecular dynamics simulations. Focus is given on two vastly different n-C materials.

The first one consists of diamond nanocrystals in a-C. It is shown [1] that nanodiamonds are stable in only dense, tertrahedral a-C matrices. The films exhibit high strength and hardness, and extreme elastic moduli approaching those of diamond [2], making them ideal for ultrahard coatings and MEMS/NEMS devices. Furthemore, our simulations elucidate for the first time the deformation properties and fracture mechanisms of n-C films.

The second nanomaterial discussed here consists of C nanotubes embedded in low-density a-C matrix [3]. It is shown that van der Waals forces are crucial in shaping up the interfacial geometry, producing a curved graphitic wall surrounding the tubes without direct bonding to the matrix. This might lead to films with excellent thermal and electrical conductivity in the tube direction.

[1] M.G. Fyta, I.N. Remediakis, and P.C. Kelires, Phys. Rev. B 67, 035423 (2003). [2] M.G. Fyta, I.N. Remediakis, P.C. Kelires, and D.A. Papaconstantopoulos, Phys. Rev. Lett. 96, 185503 (2006). [3] M.G. Fyta and P.C. Kelires, Appl. Phys. Lett. 86, 191916 (2005).

 

Legal notice
  • Legal notice:
 

Related papers

Presentation: Invited oral at E-MRS Fall Meeting 2006, Symposium A, by Pantelis C. Kelires
See On-line Journal of E-MRS Fall Meeting 2006

Submitted: 2006-05-15 06:33
Revised:   2009-06-07 00:44