A Study Regarding Dielectric Response and ac Electrical Conductivity of Schottky Structures (SSs) Interlaid with (Fe3O4-PVA) by Using Dielectric Spectroscopy Method

This study aims to reveal the complex-dielectric permittivity, complex electric modulus, complex impedance, and ac electrical conductivity of the SS interlaid with Fe₃O₄-PVA. For this intent, impedance measurements were actualized in the frequency range of 0.1–1000 kHz and the voltage range of (– 5) – 7 V. The computed dielectric parameters via impedance measurements were presented as functions of both frequency and voltage to uncover their impacts on dielectric response, polarization, and conductivity. The dielectric parameters presented as a function of voltage showcase discernible zenith demeanor amid (– 1) and 0 V, and this behavior becomes more noticeable for low frequencies. These corollaries indicate that the source of zeniths is the surface states and their distribution in the forbidden band gap of the semiconductor. On the other hand, \(\:{\epsilon\:}^{{\prime\:}}\), \(\:{\epsilon\:}^{{\prime\:}{\prime\:}}\), tanδ values presented as a function of frequency exhibit a decrement trend with frequency increment, and frequency independency at higher frequencies. This frequency-related behavior of the dielectric parameters signifies the dominance of the Maxwell-Wagner and space charge polarization in the material. Further, the Nyquist diagrams of the SS confer one single semicircular arc corresponding to a Debye-type single relaxation process. Additionally, the conduction mechanism of the structure was scrutinized via the slope of the lnσ_ac -lnω plot. The slope values smaller than the unit signify that the hopping of mobile charges dominates the conduction. All these experimental ramifications denote the preponderant effects of frequency and voltage on the dielectric response of the structure.