Characteristics of microstructure and deuterium absorption capacities of Sc films as a function of substrate temperature

• Published in: Materials letters 2012-04, Vol.72, p.46-48
• Main Authors: Wu, Qing-Ying, Bing, Wen-Zeng, Long, Xing-Gui, Zhou, Xiao-Song, Liu, Jin-Hua, Luo, Shun-Zhong
• Format: Article
• Language: English
• Subjects: absorption; deuterium; Deuterium absorption capacity; evaporation; Microstructure; molybdenum; Oxidation; Physical vapor deposition; Scandium; temperature; Thick films
• ISSN: 0167-577X; 1873-4979
• DOI: 10.1016/j.matlet.2011.12.073

Scandium thick-films have been deposited on molybdenum substrates by electron-beam evaporation and then transferred to deuteride. Here, we study the effects of substrate temperature (≈473 or 923K) upon the initial Sc microstructure and subsequent capacity of deuterium absorption. We find that low temperature leads to a porous fibrous structure with a narrow width, and high temperature results in a compact columnar structure with larger grain sizes. Through degassing and deuterium loading processes, both the atomic ratios Δ(D/Sc) are less than the stoichiometric ratio. It is smaller for the film deposited at 473K (~0.98) than that at 923K (~1.32). We hypothesize that this may arise from the more oxidation in the porous film than that in the compact one. ► The effect of substrate temperature (473K, 923K) on the Sc films is studied. ► Higher temperature leads to a compact columnar structure with the larger grain sizes. ► Lower temperature results in a porous fibrous structure with the smaller grain size. ► With the poor degassing vacuum, films with lower densification are oxidized easily. ► The atomic ratio ΔD/Sc of the film deposited at 473K is smaller than that of 923K.