Size-dependent elastic moduli of platelike nanomaterials

A semicontinuum model is presented for nanostructured materials that possess a platelike geometry, such as ultra-thin films. In contrast to the classical continuum theory, the current model accounts for the discrete nature in the thickness direction. In-plane Young's modulus, and in-plane and out-plane Poisson's ratios are investigated with this model. It is found that the values of the Young's modulus and Poisson's ratios depend on the number of atom layers in the thickness direction and approach the respective bulk values as the number of atom layers increases. (C) 2003 American Institute of Physics.