702946.fig.0016a
(a)
702946.fig.0016b
(b)
Figure 16: (a) Variation of the impedance phase angle, , with frequency at different temperatures (255°C, 340°C, 400°C, 450°C, 500°C, and 700°C). (b) Variation of the impedance phase angle, , with frequency at a few important temperatures (570°C, 573°C, and 600°C).