Sohail Ahmad, Majid Niaz Akhtar, Sijie Zhang, Fatimah Mohammed A. Alzahrani, Imran Shakir, Muzamil Ahmed Warsi, Kamal Mustafa, Sagr Alamri, Tayba Chudhary, M.S. Al-Buriahi, Muhammad Azhar Khan
The lightweight and superior absorption capabilities of microwave materials are essential for resolving electromagnetic issues in stealth technologies. This study focused on rare earth Nd3+-doped spinel nanoferrites with the formula Zn0·5Co0·5Fe2-xNdxO4 (x = 0, 0.01, 0.02, and 0.03) via a sol-gel self-ignition method to investigate their potential as high-performance microwave absorbers. X-ray diffraction indicates a single-phase cubic spinel structure (Fd-3m), with crystallite sizes varying from 25.31 nm (Scherrer) to 79.57 nm (W–H technique). Rietveld refinement yielded a dependable fit with χ2 values ranging from 1.86 to 1.95, affirming superior structural quality. The lattice constant increased from 8.391 Å to 8.434 Å with higher Nd3+ concentration, alongside a rise in microstrain. Optical investigations revealed a decrease in bandgap from 2.41 eV to 1.97 eV, signifying enhanced light absorption. FTIR and Raman spectroscopy indicated alterations in vibrational modes and metal–oxygen bonding resulting from Nd3+ substitution. XPS investigation verifies the presence of Co, Zn, Nd, Fe, and O elements at specific binding energies. Nd3+-doped spinel ferrite at x = 0.03 has the most varied particle morphology, characterised by distinct rectangular and polyhedral forms with smaller spherical particles. Magnetic measurements indicated a soft magnetic behaviour with a saturation magnetization (Ms) of 66.26 emu/g, a coercivity (Hc) of 91.14 Oe, and a magnetic moment of 2.83 μB at x = 0.03. Dielectric and impedance analysis were employed to elucidate the mobility of charge dynamics pertinent to high-frequency applications. The absorptivity of the Nd3+-doped Zn–Co-based metasurface absorbers increases with frequency. Moreover, the absorption also increases with the excitation angles in all the Nd3+-doped Zn–Co-based meta absorbers in the newly designed absorber. The Nd3+-doped Zn–Co ferrites exhibited superior microwave absorption, achieving a minimum reflection loss (RL) of −71.54 dB at 13.86 GHz and an effective absorption bandwidth (EAB) of 5.2 GHz, thereby validating their capability to reduce electromagnetic pollution via effective electromagnetic interference (EMI) shielding in the X and Ku band regimes. © 2025 Elsevier B.V.
School of Mechanical Engineering, Guizhou University of Engineering Science (GUES), Guizhou, 551700, China; School of Science, Guizhou University of Engineering Science, Bijie, 551700, China; College of Physics, Sichuan University, Chengdu, 610065, China; Institute of Physics, The Islamia University of Bahawalpur, Bahawalpur, 63100, Pakistan; Mechanical and Industrial Engineering Department, Engineering Faculty, Universitas Negeri Malang, 65145, Indonesia; Department of Chemistry, College of Sciences, Princess Nourah bint Abdulrahman University, P.O. Box 84428, Riyadh, 11671, Saudi Arabia; Department of Physics, Faculty of Science, Islamic University of Madinah, Madinah, Saudi Arabia; School of Materials Science and Engineering, Beijing Institute of Technology (BIT), Beijing, 100081, China; Department of Mechanical Engineering, College of Engineering, King Khalid University, Abha, 61421, Saudi Arabia; School of Chemistry, Zhejiang University, Hangzhou, 310027, China; Department of Physics, Sakarya University, Sakarya, Turkey; Center for Engineering and Technology Innovations, King Khalid University, Abha, 61421, Saudi Arabia
