Dielectric Properties of Fly Ash-Derived Zeolite: Frequency Response and Conduction Mechanism

Abstract

This study investigates the dielectric response of zeolite synthesized from fly ash, an abundant
industrial byproduct, and compares its performance with conventional zeolites. Pellets
prepared with silver electrodes were analyzed using impedance spectroscopy in the frequency
range of 1 kHz to 1 MHz. The dielectric constant (ε′) exhibited strong frequency dependence,
decreasing with increasing frequency, while the dielectric loss (tan δ) was higher at low
frequencies due to space charge effects and stabilized at higher frequencies. AC conductivity
(σ_ac) followed Jonscher’s universal power law, confirming hopping conduction as the
dominant mechanism. Although the fly ash-derived zeolite displayed slightly lower dielectric
constant and marginally higher losses than conventional zeolites A and ZSM-5, its high-
frequency dielectric stability and conductivity were nearly identical. These findings
demonstrate that fly ash zeolite can serve as a cost-effective, sustainable alternative to
conventional zeolites for dielectric and sensor applications.