Basic R-C circuit

This circuit is representative of a conductive solution with conductance inversely proportional to the R-parameter. At low frequencies a blocking fully capacitive interface emerges where only the double-layer charging represented by the capacitor C is present. Total impedance of the circuit and its real and imaginary components can be expressed as  

FIGURE 4-1 A. R-Ccircuit diagram and corresponding B. Nyquist and Bode C. totai impedance D. phase angle plots 

Using Eq. 1-2 for resistance R and Eq. 1-3 for capacitance C, which are frequency-dependent parameters when analyzed over a broad frequency range, a general impedance equation (Eq. 1-10) can be developed as a function of the frequency-dependent characteristic electrical properties of the analyzed material or system. This expression takes into account the frequency-dependent values of relative permittivity e((o) and resistivity p(co) or its inverse, electrical conductivity a(co), combined with the geometry factors of the electrode surface area (/4) and the sample s thickness between the bounding electrodes (d)  

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