Tunable dielectric and electrical properties of Mn-substituted Co–Zn ferrites for high frequency applications

Ferrite materials have attracted considerable attention because of their tunable structural, dielectric, and electrical properties for high-frequency applications. In this work, Co 0 . 6 Zn 0 . 4 Mn x Fe 2− x O 4 ferrites (x = 0–1.0) were synthesized using the conventional solid-state reaction method to investigate the influence of Mn substitution on their structural and dielectric behavior. X-ray diffraction analysis confirmed the formation of a single-phase cubic spinel structure with space group Fd–3 m. The lattice parameter increased systematically from 8.360 to 8.492 Å with increasing Mn concentration, indicating lattice expansion induced by Mn incorporation. Furthermore, the sample with x = 1.0 exhibited reduced micro-strain (3 . 7847 × 10 −5 ) and an average crystallite size of approximately 32.7 nm, suggesting improved structural stability. Dielectric measurements revealed a strong frequency dependent response governed by interfacial polarization and defect-related charge transport mechanisms. Higher Mn concentrations significantly enhanced the real and imaginary dielectric constants, AC conductivity, and dielectric loss compared with low Mn-substituted compositions. These findings demonstrate that Mn-induced structural modification plays an important role in tailoring the dielectric and electrical performance of Co–Zn ferrites, making them promising candidates for electromagnetic interference shielding and microwave absorption applications. • The highest dielectric constants were obtained with Mn substituted (0.4 and 1.0), along with increased dielectric losses. • When Mn was substituted at x = 0.2, the lattice’s volume rose to 612 Å3 while micro-strain decreased concurrently. • Lattice defects and electron hopping cause these compositions to have high AC electrical conductivity. • Enhanced dielectric behavior is correlated with XRD structural changes, such as reduced crystallite size, stronger micro-strain, and lattice distortions. • While other compositions support steady energy storage, the results show aptitude for microwave heating, electromagnetic wave absorption, and electromagnetic interference shielding.