Low-Temperature Anelastic Property of Nanocrystalline Ag Fabricated by Gas Deposition Method

It was reported that the internal friction (Q-1) of nanocrystalline (n-) Au and n-Cu showed a rapid increase linearly with temperature above ~200 K. Since the rapid increase in Q-1 decreased with the progress in the grain growth, it was suggested that the anelasticity of grain boundaries in n-Au and n-Cu was thermally activated above ~200 K. In order to pursue the intrinsic behavior of the grain boundaries in n-metals, the internal friction of n-Ag was measured and the result was compared with those of n-Au and n-Cu. Similar to n-Au and n-Cu, Q-1 of n-Ag was also showed the increase linearly with temperature above ~200 K. However, the onset temperature for the linear increase in Q-1 of n-Ag was slight lower than those of n-Au and n-Cu and it can be attributed to the lower activation energy of the grain boundary self-diffusion in Ag.