The prediction of the mechanical stiffness of the silicon based crystalline/amorphous nano-structures using molecular dynamic (MD) simulation

The mechanical stiffness of the silica nano-structures,including the crystalline silicon and amorphous silica, is studied using the molecular dynamics (MD) method. The MD simulation procedure is based on the linear-elastic theory, and the stiffness parameter can be acquired by the reaction forces of the sample. Moreover, we also propose a molecular structure generation algorithm for the amorphous silica, which is a low-dielectric material (SiOC:H). In the simulation of crystalline silicon, the results shows good approach to the experimental results and the size effect of the nano-structures was captured. Moreover, the simulation of amorphous silica, the trends which are indicated by the simulation results exhibit good agreements with the ones by the experiment.