Exploring Li2MgZrO4 as a multifunctional material: structural analysis, polaron conductivity, and wide bandgap for energy and optoelectronic devices

Abstract

The search for advanced materials with tunable electronic and optical properties has driven significant progress in energy storage and optoelectronic technology. Lithium-based mixed-metal oxides stand out among these materials because of their excellent ionic conductivity and structural flexibility. This study focuses on examining the structural, electrical, and optical characteristics of Li₂MgZrO₄, a ternary oxide featuring a tetragonal layered structure (space group P4₂/nmc). The material was prepared using a solid-state synthesis method and its single-phase nature was validated by X-ray diffraction analysis combined with Rietveld refinement. Additionally, scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) were employed to evaluate the microstructural features and elemental distributions of the compounds. UV-vis-NIR spectroscopy revealed a direct bandgap of 3.41 eV, highlighting the material's potential for optoelectronic applications. Impedance spectroscopy studies demonstrated a non-Debye relaxation behavior and thermally activated conductivity. Examination of AC conductivity using Jonscher's power law and the overlapping large polaron tunneling (OLPT) model revealed that polaronic conduction mechanisms primarily govern charge transport. The activation energy (0.804 eV) further supported thermally activated conduction. These results highlight Li₂MgZrO₄ as a multifunctional material with considerable potential for applications in solid-state battery design, energy storage systems, and optoelectronic innovations.