Structural and dielectric properties of Cu-doped α-ZnMoO4 ceramic system for enhanced green light emission and potential microwave applications

Abstract

In this article, the synthesis of the Zn1-xCuxMoO4 ceramic system was carried out by a solid-state reaction route, and their structural, morphological, and optical properties were investigated. The samples were characterized by X-ray diffraction, scanning electron microscopy, Raman spectroscopy, FT-IR spectroscopy, and UV–Vis spectrophotometry. Structural analysis confirms the formation of a triclinic structure with space group P $$\stackrel{-}{1}$$ and point group symmetry C1 without any secondary phase formation. The decrease in effective nuclear charge with the introduction of Cu2+ ion decreases the bandgap from 3.57 to 2.78 eV. The potential application in the visible (green) region of the electromagnetic spectrum is supported by the reduction of the bandgap. The increasing Cu2+ concentration is accompanied by Photoluminescence peaks being shifted toward larger wavelength side, covering a broad range of visible region from 300 to 600 nm. The broad range luminescence emission spectra that happened with ZnMoO4 occurred due to the electronic transition between (MoO4)2− complexes or between Mo4d and O2p states. Hakki–Coleman method was applied for the study of microwave dielectric parameters and shows increase of eobs from 8.35 to 12.52 with a simultaneous decrease in dielectric loss (tan δ) from 0.01 to 0.005, respectively. The corresponding quality factor (Q $$\times$$ f) was calculated. The observed high-quality factor could be used as high signal speed microwave materials.