Influence of Mg substitution on structural, magnetic and electrical properties of Zn-Cu ferrites

Abstract

Studies on Mg substituted Zn-Cu ferrites with chemical formula of Zn 0.6-Cu 0.4-x Mg x Fe 2 O 4 were synthesized by solid-state reaction technique. The structural phase of all the samples is characterized by XRD, show single phased cubic spinel structure. Density of the samples increases with the increase of Mg quantity. Average grain diameter decreases with increasing Mg content. All samples show soft ferromagnetic behavior as confirmed from the M-H hysteresis loop obtained from the VSM analysis. Thesaturation magnetization decreases with increasing Mg quantity. Increasing and decreasing trend of coercivity with the increase of Mg quantityis observed, which led to the slightly hard magnetic phase. The high frequencies create more effective for the ferrite grains of advanced conductivity and minor dielectric constant for all the samples but the AC electrical resistivity and dielectric constant are initiate to be more operational at lower frequencies. The variation of resistivity, dielectric constant with the Mg concentration is completely related to the porosity and bulk density.

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

“…As shown in Fig. 9, the dielectric loss factor decreases with increasing frequency, which is a normal behavior of ferrite [7,14,[18][19][20]. The dielectric loss behavior is similar to the dielectric constant due to space charge polarization [28].…”

“…Based on FTIR analysis, the assumed cation distribution of the prepared samples presented in Table 1 was assumed with the general formula [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 . The assumed cation distribution showed that Zn 2+ ions occupy only the A site, and Co 2+ ions tend to occupy B sites; however, Mn 2+ and Fe 3+ were distributed among A and B sites [11,20]. As presented in Table 1, the assumed cation distribution also showed that some Mn 2+ ions occupy B sites in Co-Zn ferrites with a ratio of 20% and 80% of Mn 2+ ions in A sites, as reported in [17].…”

“…Figure 4 shows that the D th of the prepared samples decreases with increasing Mn 2+ concentration for x ≤ 0.2 and then increases at x = 0.3. The theoretical density depends on the lattice constant and molecular weight of the sample, where theoretical density is inversely proportional to the lattice constant [7,20]. The decrease in the theoretical density can be attributed to the increase in the lattice parameter, which increases the lattice volume, leading to a decrease in the theoretical density [3,16,20].…”

“…The theoretical density depends on the lattice constant and molecular weight of the sample, where theoretical density is inversely proportional to the lattice constant [7,20]. The decrease in the theoretical density can be attributed to the increase in the lattice parameter, which increases the lattice volume, leading to a decrease in the theoretical density [3,16,20]. However, the theoretical density increased at x = 0.3.…”

“…The decrease in dielectric constant with Mn 2+ content is due to the increase in resistivity with Mn 2+ [7], which is related to the density of the samples. Consequently, it increases the porosity due to the trapped pores in the samples [20] and increases the grain boundary between the small grains [17], reducing the hopping probabilities across the grain boundaries [7,16,25]. This impedes the movement of electrons between Fe 2+ and Fe 3+ and reduces the space charge polarization.…”