Size effects in the irradiation-induced crystalline-to-amorphous transformation

Due to their unique properties, nanocrystalline composites are currently finding applications in high-radiation environments. By using zirconia (ZrO2) as an example, we show that at the smallest particle sizes, radiation damage effects can be strongly enhanced, and that under certain conditions, materials that are generally considered to be radiation resistant can become susceptible to irradiation-induced amorphization. Bulk zirconia has previously been irradiated to 680 dpa with no evidence of amorphization; however, we find that nanocrystalline zirconia can be amorphized at a dose as low as 0.9 dpa due, in part, to the energetics of the increased surface-to-volume ratio. These results have implications for the design of nanocomposite materials for use in space vehicles and in other high-radiation environments. (C) 2003 Elsevier Science B.V. All rights reserved.