Role of Mn2+ ion in the optimization of the structural and dielectric properties of Co–Zn ferrite

Abstract

Mn-substituted Co–Zn ferrite nanomaterials with the general form Co0.8−x Mnx Zn0.2 Fe2O4 (x = 0.0, 0.1, 0.2, and 0.3) were prepared using the coprecipitation method. Based on X-ray diffraction, it can be confirmed that all samples have a single-phase cubic structure with an average crystallite size ranging from 23.46 to 32.66 nm. In addition, the lattice parameter increased from 8.32 to 8.37 Å. In this study, the theoretical density was calculated, and the Fourier-transform infrared spectra of the prepared samples were investigated. Further, the cation distribution of the system was estimated. The proposed cation distribution was confirmed by calculating the theoretical lattice parameter and comparing it with the experimental lattice parameter. We conducted transmission electron microscopy to confirm the obtained particle size. At room temperature, the electrical measurements of the prepared samples were performed using the LCR circuit as a function of frequency up to 5 MHz. In this study, we obtained enhanced dielectric properties by substituting Mn ions in the Co–Zn ferrite. As the Mn concentration increases, the AC resistivity of the samples increases. Consequently, the dielectric loss decreases, and its minimum value can be observed at x = 0.2, making the Co–Mn–Zn ferrite suitable for applications in the microwave frequency range. The results show that all dielectric properties exhibit a normal behavior with frequency. We obtained an improvement in the dielectric properties of the prepared samples, making them suitable for use in high-frequency applications due to the substitution by Mn ions.

Effect of Mn2+ Substitution on Structural and Magnetic Properties of Co-Zn Ferrite

“…6 According to XRD reference card (JCPDC card no.22-1086) for CoFe 2 O 4 , XRD peaks were indexed with their Miller indices as (220), (311), (400), ( 422), (511), and (440). 1,4,6 The pattern confirms the formation of single-phase spinel structure as a major phase without any peaks belong to internal stress and a small minor phase indicated by (*) but with very small intensity. Well-defined sharp diffraction lines were observed in the samples, that proved the good crystallization without any impurities.…”

“…The distribution of cations for the prepared samples is suggested based on the reports available in the literature. 6,7 It is noted that the smaller ions such as Zn 2+ ions only occupy the smaller spaces of the lattice, hence, Zn 2+ ions only occupy the tetrahedral sites because the tetrahedral (A) sites are smaller than those at the octahedral [B] sites in the spinel ferrites and Co 2+ ions occupy the octahedral sites. 1,6,7 On the other hand, the Mn 2+ ions get distributed over tetrahedral sites (80%) and octahedral sites (20%).…”

“…6,7 It is noted that the smaller ions such as Zn 2+ ions only occupy the smaller spaces of the lattice, hence, Zn 2+ ions only occupy the tetrahedral sites because the tetrahedral (A) sites are smaller than those at the octahedral [B] sites in the spinel ferrites and Co 2+ ions occupy the octahedral sites. 1,6,7 On the other hand, the Mn 2+ ions get distributed over tetrahedral sites (80%) and octahedral sites (20%). 6,7 The distribution of cations proposed according to the study 6 is as follows: [Zn 0.2 Mn 0.8x Fe 0.8-0.8x ] A [Co 0.8−x Mn 0.2x Fe 1.2+0.8x ] B O 4 .…”

“…It was then cooled until the precipitation reaction was completed. Our past report 6 provides a more thorough explanation of the synthesis process.…”

“…1 as synthesized in. 6 In this method, to form a clear solution, high purity of Fe 2 SO 4 .XH 2 O, CoSO 4 .7H 2 O, ZnSO 4 and MnSO 4 .H 2 O were dissolved in distilled water then mixed together. To dissolve the reactant completely, the mixture was combined in a beaker and stirred for few minutes by a magnetic stirrer.…”