Ag-based delafossite structure prepared by solid-state reaction: investigation of optical, electrical, and dielectric properties

A^IB^IIIO₂ delafossite-type oxide materials have garnered considerable attention due to their significant physical and chemical characteristics, which have expanded their applications across various devices. This research examines AgCrO₂, highlighting its advantageous optical and electrical properties. X-ray diffraction (XRD) analysis confirms that the studied sample is well-crystallized in an orthorhombic structure with an <i>R</i>3̄<i>m</i> space group. The studied compound with a particle size of 1.75 μm was identified using transmission electron microscopy (TEM). The band gap energy was determined through UV-visible spectroscopy and was found to be 2.8 eV. A detailed analysis of Nyquist plots demonstrates the sensitivity of the material's electrical characteristics to variations in frequency and temperature. Applying Jonscher's power law to the AC conductivity as a function of temperature suggests that the conduction mechanism in the temperature range of 313 K to 613 K can be explained by the correlated barrier hopping (CBH) model, with an activation energy of 0.47 eV from 313 K to 493 K and 1.03 eV from 523 K to 613 K. Parameters such as the hopping distance <i>R</i> _ω and the density of localized states N(EF) were determined. The Kohlrausch-Williams-Watts (KWW) equation was employed to analyze the asymmetric curves of the electrical modulus. Additionally, the thermal variation of permittivity was interpreted using the Maxwell-Wagner effect as described by Koop's theory. Moreover, its high capacity and electrical conductivity highlight its potential for application in optoelectronic devices.