(a)
(b)
(c)
(d)
(e)
Figure 3:
SEM of glass-ceramic samples: (a) 0 mol% SiO
2
, (b) 1.5 mol% SiO
2
, (c) 2.5 mol% SiO
2
, (d) 3.5 mol% SiO
2
, and (e) 5 mol% SiO
2
.