a

Magnetic & Innovative Materials in Nanotechnology (MIMI Nanotech) Research Lab, Physics Department, Government College University Faisalabad, P.O. Box 38000

Punjab, Pakistan.

^bAl-Muthanna University, College of Pharmacy, Muthanna State, Samawah 66001, Iraq cDepartment of Physics, Sakarya University, Sakarya, Turkey

^dDepartment of Biotechnology, College of Science, Taif University, Taif city, Saudi Arabia eElectrical and Biological Physics, Kwangwoon University, Seoul 01897, South Korea

In this study, we investigate the structural, optical, and electrical properties of Zn0.5Co0.25Cu0.25Fe2O4 (ZCCF) spinel ferrites (SFs) and its La³⁺- and Ce³⁺-substituted counterparts (ZCCLF and ZCCCF) SFs, synthesized using the sol-gel auto combustion method. The primary focus is on analyzing the temperature-dependent resistivity behavior of these SFs. All samples exhibit semiconducting behavior, with resistivity decreasing as temperature increases from 400 K to 650 K. Undoped ZCCF shows the lowest resistivity, while doping with La³⁺ and Ce³⁺ significantly increases resistivity due to disruptions in charge carrier mobility caused by lattice distortions. Ce³⁺-doped ZCCCF exhibits the highest resistivity at all temperatures, highlighting the stronger influence of Ce³⁺ compared to La³⁺ on the ferrite’s electrical properties. The magnetic properties of ZCCF, ZCCLF, and ZCCCF were analyzed, revealing distinct behaviors. ZCCF exhibited the highest saturation magnetization (68.68 emu/g) and resonance frequency (15.18 GHz), making it suitable for high-frequency applications. ZCCLF showed the highest coercivity (934.18 Oe) and anisotropy, ideal for permanent magnets, while ZCCCF displayed the lowest coercivity (46.43 Oe), indicating soft magnetic characteristics for easy magnetization switching.