Giant Dielectric Permittivity and Electronic Structure in Hydrogenated (La/Mn) Merge Codoped TiO2 Ceramics

Abstract

Titanium oxide (TiO₂) nanoparticles (NPs) codoped with (La/Mn) ions were synthesized by a hydrothermal decomposition technique. The prepared codoped NPs were hydrogenated at 400 °C and systematically studied by X‐ray diffraction (XRD), optical diffuse reflection spectroscopy (DRS), and electrical insulating measurements. The codoped solid solution (SS) NPs were prepared to be built of core/shell-like electronic nanostructures that having giant permittivity (GP) of order 10⁴, which is extremely higher than that of undoped TiO₂. The electronic nature of the built structures was described according to the foundation of the doping mechanisms. Thus, the codoping was employed in the present work to fabricate coalesce dielectric crystalline medium of GP. Two Mn-dopant concentrations were used in the present investigation for comparison. Thus, the objective of creation of GP properties was successfully achieved. Moreover, the results of the electrical measurements were analyzed according to the available models: the correlated barrier hopping (CBH) model, the polarons-hopping conduction model, and Jonsher’s AC power law.