Low-frequency giant effective permittivity of island metal films

The low-frequency effective permittivity of island metal films has been investigated as a function of the frequency of the electric field. It has been found that the low-frequency effective permittivity has a complex dependence on the measuring electric field frequency. It has been shown that, at the electric field frequency $f$ = 1 kHz, the permittivity has a positive sign $(\varepsilon\approx10^8)$. With an increase in the electric field frequency, the permittivity decreases, and in the single-layer FeNi film with a thickness $d$ = 8 $\mathring{\mathrm{A}}$ at a frequency $f\approx$ 10 kHz, it is equal to zero $(\varepsilon\approx0)$. With a further increase in the electric field frequency, the permittivity becomes negative and, at a frequency $f$ = 100 kHz, reaches the value $\varepsilon\approx -10^8$. It has been established that an increase in the effective permittivity of island metal films with a decrease in the electric field frequency is associated with the activation or tunneling processes in island films.