Size effects in the elastic deformation behavior of metallic nanoparticles

作者：Armstrong Patrick; Peukert Wolfgang^*

来源：Journal of Nanoparticle Research, 2012, 14(12): 1288.

DOI：10.1007/s11051-012-1288-4

• Size effect
• Elasticity
• Molecular statics
• Nanoparticles
• Young%26apos
• s modulus

In this work, the results of a series of molecular statics simulations to investigate the size dependence of the elastic properties of metallic nanoparticles are presented. The per-atom stiffness tensor was calculated from the derivative of the used embedded atom method potentials and, from it, lower order elastic parameters, such as the Young%26apos;s modulus or the Poisson ratio. The Young%26apos;s modulus decayed up to 30 % relative to the bulk values for 2.5 nm small particles, whereas the Poisson ratio showed an increase with decreasing particle size for most materials. Particles with a diameter of 30 nm approached the continuum values to around 1 %, marking the transition to continuum theory. The size-dependent Young%26apos;s modulus and several other material properties can be described by a simple algebraic function of the number of atoms per particle. By plotting the radial distribution of the local Young%26apos;s modulus within particles of different size, it is shown that only the outermost 2-3 atomic layers are responsible for the size-dependent change of elastic properties. Within these layers, the average atomic stiffness was found to decay linearly and independent of the particle size.

• 出版日期2012-12