SIZE DEPENDENCES OF LINEAR EXPANSION AND VOLUME ELASTICITY OF MONO- AND BIMETALLIC NANOCLUSTERS

A series of molecular dynamics experiments on cooling disordered Au, Cu, Al, Ti metal nanoparticles and Au — Cu, Ti — Al bimetallic nanoalloys using the tight-binding potential have been performed. The size dependences of the temperature coefficient of linear expansion and the elasticity modulus for mono- and bimetallic particles are obtained. In the first approximation, the size dependence of the linear expansion coefficient is inversely proportional to the corresponding dependence for the melting temperature of a nanoparticle, which correlates with an analytical model. Molecular dynamics results predict a more moderate relative increase in the linear expansion coefficient compared to the analytical model. It was found that the modulus of elasticity increases with decreasing the nanoparticle size.