ABSTRACT

We propose a multiscale model for what consists of ab initio calculation, molecular dynamics simulation and a quasicontinuum model. First, we develop the interatomic interaction of the Cu/Al2O3 interface which is reproduced on the basis of the results of rigid tensile tests of ab initio calculations. Next, we analyze the Cu/Al2O3 interface via.a quasicontinuum model, using the interlayer potential identified above. The quasicontinuum model has been developed for large-scale atomistic simulations. In this approach, the number of degrees of freedom is much reduced in comparison to molecular dynamics, so that the computational time is significantly decreased. The atomistic-scale Cu/Al2O3 interface is investigated to determine the versatility of the quasicontinuum model. Relaxation simulations of the Cu/Al2O3 interface are carried out for both "large-scale analysis" and "small-scale analysis" via a quasicontinuum model. The influence of misfit in small-scale analysis is found to be much larger than the large-scale analysis upon comparing the displacement of atoms. We conclude that the results of the atomistic simulations with different sizes of the analytical region are strongly affected by the mechanical boundary conditions, and to obtain the accurate mechanical properties of interface, it is necessary to calculate with real size we subject of. The quasicontinuum method has great potential to realize an atomistic-continuum multiscale simulation.