Structural, diffuse reflectance spectroscopy and dielectric relaxation properties of zirconium (IV) dioxide
Tariq Altalhi, Adil A. Gobouri, Laila M. Al-Harbi, Moamen S. Refat, M.M. El-Nahass, A.M. Hassanien, A.A. Atta, Emad M. Ahmed
Abstract
Structural, diffuse reflectance spectroscopy, dielectric relaxation processes and electrical conduction mechanism of zirconium (IV) dioxide were investigated. The structure of ZrO2 compound was analyzed by X-ray diffraction and infrared spectroscopy techniques. X-ray results were analyzed and fitted with Rietveld refinement using Fullprof Suite program. The utility of the diffuse reflectance UV–vis–NIR spectroscopy powerful technique is used to determine the direct energy gap of ZrO2 in powder form. Dielectric measurements (capacitance and phase angle) of ZrO2 were investigated over the frequency range 0.1 Hz–4 MHz and temperature range 303–423 K. The dielectric properties of ZrO2 in pellet form were explored over the utilized range of temperature and frequency in terms of dielectric constant, dielectric loss, dissipation factor, electrical modulus, electrical conductivity and complex impedance (Cole–Cole impedance). The dispersion curves of the complex impedance (Z′(ω) and Z"(ω)) of the ZrO2 pellet show a single semicircular arc over the utilized range of temperature. The analysis of the real part of electrical conductivity over the utilized range of temperature and frequency revealed that the predominant conduction mechanism is the correlated barrier hopping (CBH) model.