(a)
(b)
(c)
(d)
(e)
(f)
(g)
(h)
Figure 2:
SEM images of the Cu
52.5
Hf
40
Al
7.5
amorphous ribbon etched in different acid solutions (a) 0.5 M HF for 4 min; (b–f) 0.05 M HCl for (b) 6 h, (c) 8 h, (d) 14 h, (e) 20 h, and (f) 24 h; (g-h) EDS analysis in (f): (g) point A (h) point B.