Sohail Ahmad, Asad Ur Rehman Khan, Majid Niaz Akhtar, Sijie Zhang, Kamal Mustafa, Fatimah Mohammed A. Alzahrani, Muhammad Ramzan, Imran Shakir, Magbool Alelyani, M.S. Al-Buriahi
High-performance, lightweight microwave absorbers are necessary for stealth and enhanced electromagnetic shielding. In this study, Ca–La co-doped BiMnO3 manganites (CaxLa0.5-xBi0.5MnO3, x = 0–0.10) were synthesised by the sol–gel route to explore the interplay between structural distortion, charge dynamics, and magnetodielectric coupling. X-ray diffraction confirmed the orthorhombic perovskite structure with local monoclinic distortions induced by A-site ionic mismatch. Co-doping with Ca2+ and La3+ effectively tuned the Mn3+/Mn4+ ratio, enhancing carrier mobility and dielectric polarisation. Magnetic measurements revealed a controlled decrease in saturation magnetisation with increasing Ca content, attributed to strain and domain-wall pinning effects. Dielectric analysis showed frequency-dependent relaxation consistent with Maxwell–Wagner polarisation, while impedance and conductivity results confirmed improved charge transport. The optimised composition (x = 0.05) achieved a minimum reflection loss of −72.54 dB at 9.57 GHz, attributed to synergistic dielectric, conductive, and interfacial losses. This work establishes a structure–property correlation demonstrating that A-site engineering in BiMnO3-based perovskites is an effective route to enhance magnetodielectric coupling and broadband microwave absorption. © 2025 Elsevier Ltd and Techna Group S.r.l. All rights are reserved, including those for text and data mining, AI training, and similar technologies.
School of Mechanical Engineering, Guizhou University of Engineering Science (GUES), Guizhou, 551700, China; Institute of Fine Organic Chemicals & Organic Materials, School of Chemistry and Chemical Engineering, Wuhan University of Science and Technology, Wuhan, 430081, China; Institute of Physics, The Islamia University of Bahawalpur, Bahawalpur, 63100, Pakistan; Mechanical and Industrial Engineering Department, Engineering Faculty, Universitas Negeri Malang, 65145, Indonesia; School of Science, Guizhou University of Engineering Science, Bijie, 551700, China; College of Physics, Sichuan University, Chengdu, 610065, China; School of Material Science and Engineering, Beijing Institute of Technology (BIT), Beijing, 100081, China; 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 Madina, 42351, Saudi Arabia; Department of Radiological Sciences, College of Applied Medical Science, King Khalid University, Saudi Arabia; Department of Physics, Sakarya University, Sakarya, Turkey
