High resistance and giant permittivity study of Ni0.4Zn0.6Fe2O4 spinel ferrite as a function of frequency and temperature

Study of the structural, electrical, dielectric properties and transport mechanisms of Cu0.5Fe2.5O4 ferrite nanoparticles for energy storage, photocatalytic and microelectronic applications

“…It shows the existence of a single relaxation peak for each temperature indicating the beginning of the process of an electrical relaxation phenomenon in this compound [ 68 ]. These humps are explained by Koop’s phenomenological theory and the interfacial polarization model [ 69 , 70 ]. According to these models, the spinel ferrite structure is considered to be formed of two layers: a layer of highly conductive grains, separated by a layer of relatively thin and poorly conductive grain boundaries.…”

“…In this region, the electronic exchange between the electric dipoles no longer follows the increase in the frequency of the external electric excitation, hence the slow decrease in permittivity [ 19 ]. This evolution of the dielectric behaviour is explained by the phenomenological theory of Maxwell-Wagner [ 69 ] and the Koop theory [ 70 ]. The dielectric structure of ferrite materials is composed by grains of conductive nature separated by grain boundaries of resistive nature.…”

Unveiling the impact of Ni2+/Y3+ co-substitution on the structural, dielectric, and impedance properties of multiferroic spinel ferrite for hydroelectric cell application

“…From Table 2, it can be seen that few Co 2+ ions were present at tetrahedral sites and few Fe 2+ ions occupied the octahedral lattice positions, as confirmed from their Wayckoff positions. 25,26 It can also be observed that the Ni 2+ ions replaced Co 2+ ions at the octahedral sites, while Y 3+ substituted the Fe 3+ ions at the tetrahedral positions. However, a very small amount of Co 2+ ions occupied the tetrahedral sites, which was due to their bi-valency.…”

Experimental Investigations on the Electrical Conductivity and Complex Dielectric Permittivity of ZnxMn1−xFe2O4 (x = 0 and 0.4) Ferrites in a Low-Frequency Field

“…The experimental dependence of lnσDC on T −1/4 of the samples, using Equation ( 5), is shown in Figure 9. The measurement error of lnσDC is approximately 1% and is represented in Figure 9a From Figure 9, one can observe that, for sample A of manganese ferrite, there is a change in the slope of the curve at a temperature of 84 °C; this fact is both due to the ferrite From Figure 9, one can observe that, for sample A of manganese ferrite, there is a change in the slope of the curve at a temperature of 84 • C; this fact is both due to the ferrite nanoparticles (grains) but also to the separation limits between the nanoparticles (grain boundaries) [40,42], which cause the sample conductivity to change. This result is in agreement with one obtained in Figure 6a, in which the plot dependence ln(τ) on (1000/T) changes its slope at a temperature of 85 • C, causing an increase in electrical conductivity (above 85 • C).…”

“…nanoparticles (grains) but also to the separation limits between the nanoparticles (grain boundaries) [40,42], which cause the sample conductivity to change. This result is in agreement with the one obtained in Figure 6a, in which the plot dependence ln(τ) on (1000/T) changes its slope at a temperature of 85 °C, causing an increase in electrical conductivity (above 85 °C).…”