Low dielectric loss, and enhanced magneto-dielectric properties of Cu0.5Cd0.5-CoFe2O4 ferrites via Co2+ substitution

Spinel ferrites (SFs) with composition Cu0.5Cd0.5−xCoxFe2O4 (x = 0.0, 0.125, 0.25, 0.375, 0.5) were prepared via the effective and low-cost sol-gel auto combustion process. X-ray diffraction confirmed the single-phase spinel matrix. Furthermore, with increasing Co2+ ions doping the lattice constant (a) was reduced and crystal size increased. The variation in two major absorption and vibration bands at tetrahedral and octahedral sites also confirmed the substitution of dopant ions in lattice sites. Moreover, the bandgap energy was measured using UV–visible analysis and was increased with the doping of Co2+ and was 2.44 eV for x = 0.375. At 313 K, the highest electrical resistivity and activation energy were 7.17 × 108 Ω cm and 0.44 eV, respectively for the sample x = 0.375. The maximum dielectric constant and tangent loss was observed, while the Q factor was minimum for sample x = 0.375 (as clear from the graphical abstract). The coercivity was 536.82 Oe and saturation magnetization had a value of 128.49 emu/g with microwave frequency 28.40 GHz for sample x = 0.375. The following results suggested that the sample with x = 0.375 is useful for high-frequency resonant circuits and multilayer chip inductors applications.