Low-frequency giant effective permittivity of island metal films

Abstract

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 (e ≈ 108). With an increase in the electric field frequency, the permittivity decreases, and in the single-layer FeNi film with a thickness d = 8 A at a frequency f ≈ 10 kHz, it is equal to zero (e ≈ 0). With a further increase in the electric field frequency, the permittivity becomes negative and, at a frequency f = 100 kHz, reaches the value e ≈–108. 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.