Investigations on structural and electrical properties of ZnO based nanoparticles and composite

Diluted magnetic semiconductors (DMS) have emerged as promising candidates for spintronic devices, offering a unique combination of semiconducting and magnetic properties. In the present study, ZnO (Z) and Zn _0.2 Cu _0.8 O (C) nanostructured materials were synthesized using sol–gel and co–precipitation methods, respectively. Their composite, ZnO: Zn _0.2 Cu _0.8 O (ZC), was fabricated to investigate the structural and electrical properties. X–ray diffraction (XRD) analysis confirms the hexagonal wurtzite phase and reveals a reduced crystallite size and suppressed lattice strain across the lattice of ZC composite, as compared to the pure phases (i.e. Z & C). Rietveld refinements and Williamson–Hall (W–H) analysis further established changes in lattice parameters and strain effect. The dielectric constant, measured for a frequency range between 20 Hz and 2 MHz, shows a significant enhancement in its values for composite material which can be attributed to the interfacial polarization and oxygen vacancies. Impedance spectroscopy reveals lower impedance in the ZC composite indicating better conduction pathways due to enhanced defect density and grain boundary interactions. AC conductivity, analyzed using Jonscher's power law, demonstrates that the correlated barrier hopping (CBH) mechanism governs the conduction, with ZC composite sample exhibiting the highest conductivity among all the three samples. These findings suggest that the composite exhibits improved dielectric and electrical performance due to synergistic effects between ZnO and Zn _0.2 Cu _0.8 O phases, making it a promising material for electronic and optoelectronic applications.