Semnan University Press Progress in Physics of Applied Materials 2783-4794 5 1 2025 11 01 Ni-Doped Cu10%/YIG Nanoparticle-Based Metamaterials: Synthesis and Electromagnetic Property Investigation at Terahertz Frequencies 31 38 9305 10.22075/ppam.2024.35886.1122 EN Fatemeh Delkhosh Department of Solid-State Physics, University of Mazandaran, Babolsar, 4741695447, Iran Ali Bahari Department of Solid-State Physics, University of Mazandaran, Babolsar, 4741695447, Iran Reza Gholipur Department of Physics, Faculty of Science, Razi University, Kermanshah, Iran Journal Article 2024 11 11 In this study, we examine the negative electromagnetic properties and refractive index in yttrium iron garnet (<em>YIG</em>) -based nanocomposites, specifically <em>Cu10%/YIG</em> and nickel-doped <em>Cu10%/YIG</em>, synthesized via an in-situ method. Field Emission Scanning Electron Microscopy (FESEM) analysis confirmed the successful formation of the target nanostructures. Particle size distribution analysis indicated an approximately normal and uniform distribution across the <em>YIG</em> nanoparticles. UV spectroscopy verified that the electronic structure and optical properties of the samples matched predicted characteristics Measurements of dielectric permittivity and magnetic permeability were conducted at room temperature using scattering parameters from a Vector Network Analyzer (VNA) and processed through MATLAB software. The results showed simultaneous negativity in both ε and μ within certain frequency ranges, confirming the potential for a negative refractive index.This feature opens promising opportunities for advanced electromagnetic wave control, with implications for optical, communication, and electronic technologies. https://ppam.semnan.ac.ir/article_9305_39629045510edf771083677f9077bf89.pdf