List of symbols for corrosion research

Here you will find all the symbols used used by us in this knowledge base. Please note that other publications might use different symbols for the same parameters.


Symbol Explanation
[A] concentration of A
ßanodic Tafel slope for oxidation
derivative of x with respect to y
ε0 electric field constant
εr relative permittivity
Φ phase shift
φ CPE parameter: 0 Resistor, 1 Capacitor
τ time constant of a capacitor (τ = RC)
a activity
aOx activity of the oxidized species
aRed activity of the reduced species
A area
c concentration
cb bulk conentration
cOx concentration of the oxidized species
cRed concentration of the reduced species
C capacity
CC coating capacity
Cdl double layer capacity
CE counter electrode
d distance
E potential
E0 standard potential
E0 formal potential
EC charging potential applied to a capacitor
Ecorr corrosion potential
Epp primary passivation potential
Estep step potential during DPV and SWV
ET transmission potential for passivation film
fOx activity coefficient of the oxidized species
fRed activity coefficient of the reduced species
F faraday constant
I electric current
I0 current at t = 0
Icap capacitive charging current
Icorr corrosion current
Icrit critical passivation current
Ipas passive current / current for passivated material
k reaction rate
KL solubility product
n amount of substance / order of reaction
Ox an oxidized species
Q charge
r reaction rate
R resistance or universal gas constant
Rpor pore resistance
Rsol Solution resistance
RU uncompensated resitance
RE reference electrode
Red a reduced species
t time
tinterval time between two point of measurement
T temperature
U voltage
v scan rate
vs versus
WE working electrode
z electrons transferred per molecule
Z impedance
ZCPE impedance of the CPE
ZW Warburg impedance


Potentiostats: use, compounds, disadvantages and function