Helium desorption behavior and growth mechanism of helium bubbles in FeCrNi film. (December 2019)

• Record Type: Journal Article
• Authors: Wang, L.; Wang, X.P.; Zhang, L.F.; Gao, Y.X.; Liu, R.; Gao, R.; Jiang, Y.; Hao, T.; Zhang, T.; Fang, Q.F.; Liu, C.S.
• Is Part Of: Nuclear materials and energy. Volume 21(2019)
• Publication Date: 2019-12
• Subjects: Magnetron sputtering -- FeCrNi film -- Thermal desorption -- He bubbles; Nuclear energy -- Periodicals; Nuclear fuels -- Periodicals; Nuclear reactors -- Materials -- Periodicals; Radioactive substances -- Periodicals; 621.4833
• DOI: 10.1016/j.nme.2019.100710
• Languages: English
• ISSNs: 2352-1791

Abstract

Highlights: He bubble size grows significantly up in He-charged FeCrNi film subjecting to the annealing from less than 1 nm in radius under room temperature to 5 nm in radius under 1073 K. Three He desorption peaks observed in TDS spectra are related to the release of interstitial He atoms from the near-surface regions, He-vacancy clusters with different sizes in He-charged FeCrNi film, respectively. It is speculated that migration coarsening (MC) mechanism plays a main role in He bubble growth in He-charged FeCrNi film. Abstract: He-charged FeCrNi films were prepared by radio frequency (RF) magnetron sputtering technique, and helium desorption behavior, growth process and evolution mechanism of helium bubbles in FeCrNi film were studied by thermal desorption spectroscopy (TDS) spectra combined with microstructure analysis under different annealing treatments. Three different He desorption peaks were observed in TDS spectra, which can be related to the release of interstitial helium atoms from the near-surface regions, helium-vacancy clusters with different sizes in FeCrNi film. TEM analysis showed that helium bubbles can be uniformly distributed in He-charged FeCrNi nanocrystalline films. Under annealing treatments at different temperatures, the size of helium bubbles obviously increases with increasing annealing temperature, corresponding to the significantly decrease in the number density of helium bubbles in FeCrNi films, and the growth mechanism of helium bubbles was suggested to originate from the migration and coalescence (MC) mechanism.