Figure 4.

Activation energy of diffusion versus the size of the nanostructure for iron (Fe) and copper (Cu). The solid lines indicate the theoretical prediction with Eq. 3. for Fe and Cu nanoparticles. The symbols are the experimental values of Fe [15] and Cu [30] nanoparticles. The activation energies of diffusion of the corresponding bulk Fe and Cu are 218 kJ/mol [15] and 69.78 kJ/mol [30]

Guisbiers Nanoscale Research Letters 2010 5:1132-1136   doi:10.1007/s11671-010-9614-1