Temperature Dependent Dielectric Studies of Zinc Doped Lithium Nanoferrites

Abstract

Lithium ferrites have gained attention nowadays because of their unique structural and transport properties. These properties can further be enhanced by adding an appropriate dopant which makes them a potential candidate for various applications. In the present work, nanoparticles of Zn-substituted Li ferrites with the nominal composition Li_0.44Zn_0.06Fe_2.5O₄ were prepared by a co-precipitation method. X-ray diffraction (XRD) was done to study the structural properties such as crystal structure, crystallite size, phase purity, and porosity of the samples. XRD revealed the spinel structure of the prepared samples. Scanning electron microscopy (SEM) was done to study the morphology, and it confirmed the particle-like morphology of the prepared sample. AC electrical properties (dielectric constant (ε), dielectric loss tangent (tan δ), ac electrical conductivity (σ _ac), and impedance (Z)) in a frequency range of 20 Hz–3 MHz were studied at 25 to 600 °C. Dielectric constant and loss tangent decreased with frequency, but σ _ac increased with increase in frequency. The magnitude of ε, tan δ, and σ _ac was observed to be increasing with increase in temperature, while that for Z, it was decreasing. Maxwell-Wagner’s model and Jonscher’s power law were used to explain the electron hopping mechanism in frequency-dependent properties.