d the distance of the plates that can be used to estimate the
thickness of the coating.
For the samples of commercially pure magnesium, the
Nyquist impedance plot and the fitting results are reported
in Fig. 13a and Table 5. Increasing the current density of
the PEO process, induced also an increase in the value of
R2, the polarization resistance, which is inversely proportional
to icorr. In detail, the R2 of the sample treated at
0.45 A cm-2 was one order of magnitude higher than the
one of the untreated sample. Moreover, a decrease in the
value of Q can be observed passing from the untreated