962073.fig.0011a
(a)
962073.fig.0011b
(b)
962073.fig.0011c
(c)
962073.fig.0011d
(d)
Figure 11: TEM micrographs of (a) as-synthesised sample B and after heat treatments at (b) 300°C, (c) 500°C, and (d) 700°C for 2 hours.