Self-diffusion and magnetic properties in explosion densified nanocrystalline Fe

The high-density n-Fe prepared by the conventional static compaction of gas-condensed nanocrystallites was further densified by the explosive compaction reaching a final density > 95% of the theoretical value. In contrast to the increase in density, the self-diffusivity for the high-density n-Fe was almost unchanged and was close to that for the conventional grain boundaries (GB) diffusion expected from the extrapolation of high temperature data. Furthermore, a high saturation magnetisation of the present high-density n-Fe was found to be much closer to the theoretical bulk-Fe value than that previously reported for poorly packed n-Fe and it showed a slight increase after the explosive compaction. These observations suggest that the behavior of the GB's in high-density gas-condensed n-metals is quite similar to that of the conventional GB's in poly-metals.