Page 144 - Corrosion Engineering Principles and Practice

118 C h a p t e r 5 C o r r o s i o n K i n e t i c s a n d A p p l i c a t i o n s o f E l e c t r o c h e m i s t r y 119

200000

160000

Imaginary (Ohm) 120000 C dl

80000
R s
W
40000 R p

0
0 50000 100000 150000 200000 250000 300000
Real (Ohm)
(a)

6 100

5 80

Log Z (Ohm) 4 60 Phase angle (°)

40
3

2 20

1 0
–3 –2 –1 0 1 2 3
Log (Frequency (Hz))
(b)
FIGURE 5.27 (a) Complex plane and (b) Bode plots of simulated data
corresponding to model circuit in Fig. 5.25(b) where R = 10 Ω, R = 100 kΩ,
p
s
C = 40 µF and the exponent n of the Warburg component = 0.4.
dl