Helium release and amorphization resistance in ion irradiated nanochannel films

Abstract

Volumetric swelling, surface blistering, exfoliation and embrittlement partially induced by the aggregation of gas bubbles are serious problems for materials in nuclear reactors. This letter demonstrates that the “vein-like” nanochannel films possess greater He management capability and radiation tolerance. For a given fluence, the He bubble size in the nanochannel film decreases with increasing the nanochannel density. For a given nanochannel density, the bubble size increases with increasing fluence initially but levels off to a maximum value of 0.8 nm after the ion fluence reaches , corresponding to He release ratio of 79% in the irradiated CrN RT films. The abundant surfaces in the nanochannel films are perfect defect sinks and thereby large sized He bubbles and supersaturated defects are less likely to be developed in these high radiation tolerant materials.