Showing papers by "Judith A. Harrison published in 1997"

Friction between Diamond Surfaces in the Presence of Small Third-Body Molecules

Abstract: Molecular dynamics simulations have been used to examine the friction between the hydrogen-terminated (111) faces of diamond with small hydrocarbon (third-body) molecules trapped between them. In general, the presence of the trapped third-body molecules reduced the friction between the diamond surfaces with the most pronounced reduction at high loads. The size and shape of the third-body molecule, as well as the alignment of atoms on opposing diamond surfaces, were found to be paramount in determining the magnitude of the friction. These results are compared to results from previous simulations that examined the effects of chemically bound hydrocarbons on the friction between diamond surfaces and to available experimental data.

Atomistic simulations of the nanometer-scale indentation of amorphous-carbon thin films

Abstract: Molecular dynamics simulations are used to examine the nanometer-scale indentation of a thin film of amorphous carbon with a nonrigid sp3 bonded carbon tip. The simulations show in detail the atomic-scale mechanism of the indentation process and compare the bonding character of the film before and after indentation. The computationally determined elastic modulus of the amorphous-carbon film is found to be 243 GPa, in good agreement with experiment.