I saw an article talking about the permittivity of a highly conductive material is very large and infinite for the perfect conductor.
The following is from efunda.com
"In general, good conductors such as metals have an essentially infinite permittivity. Finite permittivities are normally associated with dielectric materials that have bound internal charge. Much of the internal charge of metals are free to roam, and will do so in the presence of an external electric field to cancel the electric field within the metal. Hence, metals (such as silver, copper, and gold) polarize extremely strongly and thereby have an infinite permittivity."
However, in EM books, e.g., Cheng-field and wave electromagnetics, the relative permittivity is considered as 1, that is the permittivity is same to e0=8.85e-15.
Also in HFSS, the relative permittivity values of well-known conductors, copper-silver-..., are all assigned to 1.
Which one is right?
Am I confused because one is talking about the complex permittivity and the other only concerns the real part?