Ferrite System Research Articles

Structural, morphological and electromagnetic properties of Sc3+ doped Ni-Cu-Zn ferrites

Abstract Various polycrystalline Ni0.3Cu0.2Zn0.5ScxFe2−xO4 (x = 0.00, 0.02, 0.04, 0.05 and 0.07) were synthesized by standard solid-state reaction technique. The composition was calcinated at 1173 K and the samples, prepared from these powders, were sintered at 1373, 1423, 1473 and 1523 K for 5 h in air. The result of compositional variation on structural, morphological and magnetic properties of Scandium (Sc3+) doped Ni-Cu-Zn ferrites was investigated. The X-ray diffraction measurements confirmed the single-phase cubic spinel structure of these compositions, and no traces of extra peaks corresponding to any unreacted ingredient were found. Lattice constant increases with substitution of Sc3+ in the place of Fe3+. Theoretical density and bulk density decrease with the increase of Sc3+ substitution. Bulk density of Ni0.3Cu0.2Zn0.5ScxFe2−xO4 reaches the maximum value for x = 0.05 sintered at 1423 K. The average grain sizes increase with increasing Sc3+ substitution up to x = 0.05 then it starts to decrease. The real part of initial permeability decreases for x = 0.02, then it increases for x values up to 0.05 after that it decreases again for x = 0.07. The doping of Sc3+ affects the magnetization may be by alteration of the cation distribution. The maximum saturation magnetization is observed 79 Am2/kg for x = 0.05 sintered at 1423 K. At lower frequency range (up to 105 Hz) dielectric constant decreases rapidly with increasing frequency but at higher frequencies (above 105 Hz) it becomes constant and show negligibly small values which is a good agreement with the Maxwell-Wagner model. Dielectric constant and AC resistivity show similar behavior at different frequency ranges. The resistivity mechanism has been explained on the basis of electron hoping between Fe2+ and Fe3+, and it is concluded that at higher concentrations some Sc3+ may possibly occupy A-sites besides a large portion of it going to B-sites, whereas for lower concentrations Sc3+ preferentially occupy B-sites in the Ni-Cu-Zn ferrites system.

An Fe-Ni-Cr embedded atom method potential for austenitic and ferritic systems.

Fe-Ni-Cr stainless-steels are important structural materials because of their superior strength and corrosion resistance. Atomistic studies of mechanical properties of stainless-steels, however, have been limited by the lack of high-fidelity interatomic potentials. Here using density functional theory as a guide, we have developed a new Fe-Ni-Cr embedded atom method potential. We demonstrate that our potential enables stable molecular dynamics simulations of stainless-steel alloys at high temperatures, accurately reproduces the stacking fault energy-known to strongly influence the mode of plastic deformation (e.g., twinning vs. dislocation glide vs. cross-slip)-of these alloys over a range of compositions, and gives reasonable elastic constants, energies, and volumes for various compositions. The latter are pertinent for determining short-range order and solute strengthening effects. Our results suggest that our potential is suitable for studying mechanical properties of austenitic and ferritic stainless-steels which have vast implementation in the scientific and industrial communities. Published 2018. This article is a U.S. Government work and is in the public domain in the USA.

Synergistic effect of heat treatment on structural, magnetic and dielectric properties of spinel ferrite nanoparticles

Polycrystalline Ni1−xCoxFe2O4 ferrite nanoparticles (NPs) have been prepared by evaporation method in the presence of egg white as a bio-template. In this paper, the results of microstructure, magnetic and dielectric behavior of heat treated Ni0.8Co0.2Fe2O4 at 600 °C, 750 °C and 900 °C are reported. The single phase cubic structure without the traces of secondary phases was confirmed by XRD. Sintering process promotes the rate of the crystallization process and the crystallite sizes were found to be in the range of 10–22 nm. TEM micrograph revealed the shape of ferrite particles to be nearly spherical. The average particle size estimated from TEM is well matched with the crystallite size estimated from XRD. The nature of magnetization curves indicates the influence of core–shell interactions on the magnetic properties of the present ferrite system. The cation distribution estimated from XRD results excellently supports the structural behaviour. The observed increase in Co2+ ion concentration at B-site has to increase the magnetocrystalline anisotropy leading to increase in the coercivity, but opposite phenomenon was observed. A maximum value of 48 emu/g was reported for saturation magnetization. The variation of particle size played a major role in dielectric and magnetic properties. The results are interpreted in terms of cation distribution and magnetocrystalline anisotropy presuming the possible core–shell interactions.

Magnetic interactions and electrical properties of Tb3+ substituted NiCuZn ferrites

We report the electric and magnetic properties of nanocrystalline Tb3+ substituted Ni0.25Cu0.30Zn0.45TbxFe2−xO4, with x = 0.0–0.125 mol., step: 0.025 mol ferrites, synthesized by glycine assisted autocombustion route. The structural studies confirm the formation of spinel cubic structure for NiCuZn ferrites with the formation of agglomerated polydisperse grains. The presence of two intrinsic IR absorption bands of spinel lattice at ν1 (760–768) cm−1 and ν2 (650–665) cm−1 for NiCuZn ferrite system confirms the existence of tetrahedral-A and octahedral-B sites over which the cations are distributed in spinel lattice. Complex permeability measurements signified the decrease in the initial permeability due to spin canting and spin frustration by paramagnetic Tb3+ ions. The frequency dependent dielectric constant of NiCuZn ferrites revealed dielectric dispersion behavior in accordance with Maxwell–Wagner model. The incorporation of rare earth element (Tb3+) in NiCuZn ferrite at relatively lower sintering temperature (1173 K), significantly alters the structural and electromagnetic properties of the host material. Therefore, the present Tb3+ substituted NiCuZn ferrite system with moderate electrical resistivity and soft magnetic properties are potential candidate for multilayer chip inductor (MLCI) component applications.

Co2+ substituted Mg\u2013Cu\u2013Zn ferrite: Evaluation of structural, magnetic, and electromagnetic properties

We report the synthesis of Co2+ substituted Mg–Cu–Zn ferrite via citrate gel combustion process and thereby its structural, transport, and magnetic properties for the use in electromagnetic energy absorption application. The polycrystalline ferrite system is investigated by interplay of stoichiometric composition with Mg0.25–xCoxCu0.25Zn0.5Fe2O4 (0 ⩽ x ⩽ 0.25). Structural investigations using X-ray diffraction (XRD) and selected area electron diffraction (SAED) reveal the formation of spinel structure with linear growth of lattice constant due to Co2+ substitution. The microstructural analysis (TEM and SEM) depicts the dense microstructure with the average grain size of 0.42–1.25 μm. The elemental analysis (EDS) confirms the elemental composition of the as-prepared ferrite with respect to the initial concentrations of the synthetic composition used. The observed variations in initial permeability (μi) and magnetic moment (nB) are explained based on deviation in saturation magnetization (Ms), anisotropy constant (K1), density values, and exchange interaction. The temperature dependence of DC resistivity confirms the semiconducting behavior of the as-prepared ferrite material, with an increase in the DC resistivity by an incorporation of cobalt. Furthermore, the effects of adding Co2+ on the Curie temperature, frequency dependent dielectric properties of the ferrite material are also discussed.

The effect of gypsum on the hydration of alite–belite–ferrite phase system

Thermal analysis is a very effective method for the study of the hydration process of cement. This paper focuses on the interactions between the alite–belite–ferrite phase system and different amounts of gypsum by isothermal calorimetry and thermogravimetric analysis. These heat evolution results show that the addition of gypsum could shorten the induction period and promote to a higher hydration rate in the acceleration period. XRD analysis results show that the gypsum mainly promotes the hydration rate of alite at early age and the hydration rate of alite is faster than ferrite phase. Moreover, no observable differences are recorded in the hydration rate of alite–belite–ferrite phase system in the later stage according to the values of hydration degree calculated by the method of Monteagudo. Lastly, the compressive strength of the alite–belite–ferrite phase system with gypsum increases with the increasing amounts of gypsum at all ages up to 28 days. The sample with 5 mass% gypsum shows the best performance in terms of the mechanical property development. The proper concentration of sulfate is beneficial to the hydration process of alite–belite–ferrite phase system.

Rietveld, cation distribution and elastic investigations of nanocrystalline Li0.5+0.5xZrxFe2.5-1.5xO4 synthesized via sol-gel route

The present report deals with the structural and elastic behavior of Li+ and Zr4+ substituted spinel ferrites. Nanocrystalline spinel ferrite system of chemical formula Li0.5+0.5xZrxFe2.5-1.5xO4 (where, x = 0.0, 0.1, 0.2, 0.3, 0.4, 0.5 and 0.6) was synthesized by using sol-gel auto combustion method. The as-prepared powder was annealed at 800 °C for 5 h for better crystallinity. The annealed samples were characterized by X-ray diffraction technique and Fourier transform infrared spectroscopy for structural and elastic studies respectively. By applying the full pattern fitting of Rietveld method the x, y, z coordinates of atoms, unit cell dimensions and occupancy of ions were estimated. The lattice parameter was found to decrease after substitution due to increase in electron affinity. Site preferences of cations were obtained by matching experimental and calculated intensity. The characteristic bands of crystallographic sub-lattice for the cubic structure were observed by FTIR spectra.

Unusual increase in permeability in cobalt substituted Ni-Zn-Mg ferrites

A constant rise in magnetic permeability with a simultaneous decrease in saturation magnetization, and Curie temperature has been recorded throughout the cobalt concentration studied in Ni-Zn ferrite system of composition, Ni0.57−yCoyZn0.35Mg0.08Fe2O4 (x = 0.00, 0.04, 0.08, 0.12, 0.16, 0.20). The observed increase in magnetic permeability with cobalt addition has been an unusual phenomenon in nickel zinc ferrites. The anomalous increase along with allied magnetic properties has been discussed in terms of the super exchange interactions between the cations occupying tetrahedral and octahedral sites and their distribution by studying lattice parameter, grain size and differential magnetic susceptibility.

Influence of the Preparation Conditions and Percolation Threshold on the Properties of Lead Zirconate Titanate/Cobalt Nickel Ferrite Magnetoelectric Composites

We have prepared magnetoelectric (ME) composite ceramics, free of foreign phases, in the lead zirconate titanate–cobalt nickel ferrite two-phase system: xPZT-36 + (100–x)Ni0.9Co0.1Fe2O4. The sol–gel derived ferrite powder used in our preparations seems to be doped with titanium cations from the PZT-36. The ceramics have a percolation threshold at x = 50–70 wt %, which is due to the increased electrical conductivity of Ni0.9Co0.1Fe2O4. As a consequence, the piezoelectric parameters of the ME ceramics drop sharply at x < 50–70 wt %: the piezoelectric moduli |dij| and piezoelectric voltage coefficients |gij| decrease by a factor of 3–5 in this composite range. The piezoelectric parameters |dij| and |gij| of the composites produced using the fine ferrite powder exceed those of the materials prepared using macrocrystalline Ni0.9Co0.1Fe2O4 powder by more than a factor of 2. The piezoelectric voltage coefficient g33 correlates with the ME coefficient ΔE/ΔH. The highest ME conversion efficiency (up to 45 mV/(cm Oe)) is offered by the 80 wt % PZT-36 + 20 wt % Ni0.9Co0.1Fe2O4 composites, whose composition lies in a subpercolation region. Even though the composites produced using the fine ferrite powder possess improved piezoelectric properties, they have smaller ΔE/ΔH coefficients (no greater than 25 mV/(cm Oe)), which can be tentatively attributed to the degradation of the properties of the ferrite as a consequence of doping with Ti4+ cations during the sintering of the composite ceramics.

Structural and electron spin resonance spectroscopic studies of MnxZn1−xFe2O4 (x = 0.5, 0.6, 0.7) nanoferrites synthesized by sol-gel auto combustion method

Nanoferrites with the chemical equation MnxZn1−xFe2O4 (x = 0.5, 0.6, 0.7) were prepared by sol-gel auto combustion method in order to study their structural, elastic and electron magnetic resonance properties. The Bragg reflections in the X-ray diffractograms matched with the formation of cubic spinel phase along with the secondary phases of α-Fe2O3 and Mn2O3. The uneven variation of lattice parameter was found to be depending on the possible cation redistribution in the spinel structure/or grain sizes. From the histograms of SEM studies, the composition x = 0.6 comparatively has a narrow distribution of grain sizes (5–11 μm) than those of compositions x = 0.5 (3.5–8.5 μm) and x = 0.7 (2.5–8.5 μm). The higher and lower vibrational frequencies in the FTIR spectra occurred around 560 cm−1 and 470 cm−1 confirm the cubic spinel phase of present ferrite systems in the line of XRD confirmation. The change in the vibrational frequencies supports the variation of lattice parameter. The variation of lattice energy is supportive for the elastic properties, but not to the structural parameters. The same value of Poisson’s ratio (∼0.35) for the three compositions is an indicative, representing the isotropic behaviour of spinel ferrite systems. The range (2.012–2.106) of Lande’s g-parameter indicates the change in Fe3+–O–Fe3+ superexchange interaction. The results are interpreted based on the possible cation redistribution, the secondary phases presuming the core-shell interactions.

Investigation of Structural Parameters and Magnetic Properties of Mixed Li-Ni Spinel Ferrites

The solid state method was used to synthesize the mixed spinel ferrites where x is the increments of Ni content. The net magnetization (Mnet) of the prepared samples was calculated according to the suggested cations distribution . The calculated magnetization of tetrahedral (Td) site (MT) unchanged, while the magnetization of octahedral (Oh) site (MO) and Mnet decreased due to increasing Ni2+ ions. The measured values of Mnet showed the same behavior as the calculated values, which decreased exponentially with increasing of the Ni concentrations. In addition, Mnet increased with increasing of applied magnetic field (H), which showed a normal behavior for the ferrites system. The ratio of FeT/FeO indicated that the relative number of the Fe3+ ions on Oh sites decreased with increasing Ni content. The ionic radii of Td sites ( ) unchanged where the radii of Oh sites ( ) increased with increasing of the Ni2+ ions. The values of the average ionic radii increased with increasing of Ni2+ ions. The expected values of lattice parameter ( ) increased, where the values of oxygen parameter and decreased with more incorporation of Ni content. All the interionic distances (bond lengths (BLs)) changed due to increasing of Ni contents. The bond angles , , , and were calculated. The values of , and increased and the decreased with increasing of Ni2+ ions. The relative permeability ( ) increased with increasing of the filed H and decreased with the increase in in composition x.Substitution of the Ni2+ ions has a tremendous influence on the properties of Li-spinel ferrite such the magnetic properties.

TYPES OF ACTIVE CENTERS ON SURFACE OF PROMOTED IRON OXIDE CATALYST

The phase and chemical composition of compounds in the potassium-iron-oxygen system in a wide range of molar ratios of potassium and iron was studied by X-ray phase analysis and atomic absorption spectroscopy. The catalytic properties and the mass fraction of coke deposits on ferritic systems of various composition are determined. It has been shown that at least two types of active sites are present on the surface of the iron oxide catalyst. The dehydrogenation centers include oxygen ion, ions of a promoting alkali metal, and ions of bivalent and triply charged iron, between which electron exchange takes place. Most probably such center is realized in the structure of potassium-polyferrite (K2Fe2+Fe3+10O17). The coke formation centers contain an unpromoted cluster consisting of oxygen ion and iron (III) ion, are realized in Fe3O4 and KFe11O17. Coke deposits on the surface of the catalyst block non-selective active sites and increase the selectivity of action. The probability of realization of clusters corresponding to the dehydrogenation centers is three orders of magnitude higher than in the places of phase contact, the aggregate of which contains the whole set of ions corresponding to dehydrogenation centers, for example, "magnetite + potassium monoferrite". The pure potassium β"-polyferrite provides an optimal concentration of selective centers on the surface of the catalyst, operates highly efficiently in the absence of negative external influences (catalyst re-recovery, corrosion reaction of the reaction medium, poisoning effect). Individual b²-polyferrites, like any catalytically active phase, are unstable, however, being in equilibrium with potassium monoferrate and magnetite, it is able to operate effectively for a long time and to withstand the negative effects of redox properties of the surrounding reaction medium. The presence of potassium monoferrite in the catalytically active system ensures the polyfunctionality of the action of contact, i.e. ability to self-regeneration. It is likely that in the structure of potassium monoferrite, centers for preventing coke formation and annealing of coke are realized, containing oxygen ion, iron ion, and alkaline promoter.Forcitation:Dvoretskii N.V., Anikanova L.G., Malysheva Z.G. Types of active centers on surface of promoted iron oxide catalyst. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2018. V. 61. N 6. P. 61-68

Tailoring the Physicochemical and Magnetic Properties of an Mn Substituted Cobalt Ferrite System

An Mn substituted cobalt ferrite system was prepared using a simple, low temperature auto-combustion method followed by heating at 600 °C for 3 h. In this method, the thermochemical decomposition of amino acids such as glycine at elevated temperatures in the presence of salt nitrates, especially iron nitrate, produced a ferrite system. The as-prepared Mn-Co ferrite was characterized by XRD, SEM, IR and EDX techniques. These techniques revealed that the employed preparation method led to formation of a single phase of nanocrystalline spinel Mn0.5Co0.5Fe2O4 powder. However, various structural and morphological properties of the as-synthesized ferrite were determined. Porous and agglomerated morphology of the bulk sample was displayed in the scanning electron microscopy image. The VSM technique displayed the saturation magnetism of Mn0.5Co0.5Fe2O4 as 51.53 emu/g.

Microstructure and reactivity of Fe2O3-Li2CO3-ZnO ferrite system ball-milled in a planetary mill

In this work, the microstructure of mechanically activated Fe2O3-Li2CO3-ZnO mixture for the lithium-zinc ferrites production was studied using the Brüner, Emmett, Teller and laser diffraction methods as well as X-ray diffraction and scanning electron microscopy analyses. The reactivity of reagent mixture was investigated by thermogravimetric and calorimetric analyses. The ball milling was performed in a AGO-2S high energy planetary ball mill with a vial rotation speed of 2220 rpm using steel grinding balls. The milling times were 0, 5, 15, 30 or 60 min. It was shown that the composition of mixture changes during the ball milling, which consists in decreasing the α-Fe2O3 concentration and increasing the Fe3O4 spinel phase, while the Li2CO3 and ZnO concentrations remain unchanged. It was found that the milling leads to decrease in the average particle size of the reagents and simultaneously formation of large size agglomerates with denser structure and well-interlinked particles. It was established that observed changes in microstructure and phase composition lead to an increase in the reactivity of the Fe2O3-Li2CO3-ZnO system and the acceleration of the chemical reaction between reagents.

Effect of Cu-doping on structural and electrical properties of Ni0.4−xCu0.3+xMg0.3Fe2O4 ferrites prepared using sol–gel method

ABSTRACTNi0.4−xCu0.3+xMg0.3Fe2O4 spinel ferrites were prepared by sol–gel technique. X-ray diffraction results indicate that ferrite samples have a cubic spinel-type structure with space group. The electrical properties of the studied samples using complex impedance spectroscopy technique have been investigated as a function of frequency at different temperatures. We found that the addition of copper in Ni0.4−xCu0.3+xMg0.3Fe2O4 ferrite system can improve its conductivity. Dielectric properties have been discussed in terms of hopping of charge carriers between Fe2+ and Fe3+ ions. For all samples, frequency dependence of the imaginary part of impedance (Z") shows the existence of relaxation phenomenon. The appropriate equivalent circuit configuration for modeling the Nyquist plots of impedance is of the type of (Rg + Rgb//Cgb).

Spectral, Electrical, Thermoelectrical and Dielectric Properties of (Zn,Zr) Co-doped CuFe2O4

The effects of Zr+ 4 and Zn+ 2 substitution on the electrical, dielectric and spectral properties of non-stoichiometric Cu1−xZnxZryFe2−yO4 + δ and stoichiometric Cu1−xZnx + yZryFe2 − 2yO4 ferrites prepared by double sintering ceramic technique have been investigated. IR absorption spectra confirm the formation of spinel structure. On the other hand, IR spectra can give an idea about the change of molecular structure of ferrites system due to the perturbation that occurred in Fe3+–O2− bond by introducing Zn and Zr elements. The phase identification of nonstoichiometric (ns) and stoichiometric (s) samples was confirmed by the presence of endothermic peak from DTA curves at around 936 ∘C in agreement with X-ray diffraction and IR results. The calculated low values of activation energies for conduction are in the range that suggests the conduction is due to thermally activated mobility and the presence of hopping conduction mechanism. Thermoelectric power exhibits positive sign for most s and ns samples. The concentration of charge carrier is constant in the ferromagnetic region. It is also noted that the dielectric constant decreases with increasing Zn and Zr contents. From the above discussion the samples containing Zn and Zr elements have lower ΔBpp values with low energy loss. From the ESR analysis it can be confirmed that the addition of Zn and Zr generally decrease the power loss which is very important in the application for the manufacturing of a material which is used as a core of transformer at the microwave frequencies.

Temperature-dependent physicochemical properties of magnesium ferrites (MgFe2O4)

Physical and electrochemical properties of magnesium ferrite (MgFe2O4) with respect to calcination temperature were investigated. XRD results revealed the increasing degree of crystallinity at different annealing temperatures. SEM images explored the spherical morphology of particles. High intense principal photoluminescence peak situated at 532 nm revealed spinel ferrite system assigned to 3d5 → 3d4 4s transitions of Fe3+ ions. Infrared metal–oxygen vibration observed at 580 and 441 cm−1 revealed tetrahedral and octahedral sites of ferrite system. The product showed highest specific capacitance of 119.50 F/g at scan rate 5 mV/s for the sample annealed at 500 °C and the specific capacitance noticeably decreased for increasing calcination temperature. The calcination temperature played a central role on structural, morphological, optical, and electrochemical properties of MgFe2O4.

Effect of Solutes on Grain Refinement of As-Cast Fe-4Si Alloy

Grain size is one of the key microstructural factors that control the mechanical properties of steels. The present work aims to extend the theories of grain refinement which were established for cast light alloys to steel systems. Using a designed Fe-4 wt pct Si alloy (all-ferrite structure during whole solidification process), the solute effect on grain refinement/grain coarsening in ferritic systems was comprehensively investigated. Experimental results showed that boron (B), which is associated with the highest Q value (growth restriction factor) in ferrite, significantly refined the as-cast structure of the Fe-4 wt pct Si alloy. Cu and Mo with low Q values had no effect on grain refinement. However, although Y and Zr have relatively high Q values, addition of these two solutes led to grain coarsening in the Fe-4Si alloy. Understanding the results in regards to the growth restriction factor and the driving force for the solidification led to the conclusion that in addition to the grain growth restriction effect, the changes of thermodynamic driving force for solidification due to the solute addition also played a key role in grain refinement in ferritic alloys.

Effect of La&lt;sup&gt;3+&lt;/sup&gt; Substitution on the Structural and Magnetic Properties of Mn-Zn Ferrite Prepared by Sol-Gel Auto-Combustion Method

Spinel ferrite with the chemical formula of Mn0.5Zn0.5LaxFe2-xO4 (x = 0.02, 0.04, 0.06, 0.08, 0.10) were prepared by a sol-gel auto-combustion method. The effect of the rare-earth substitution on the microstructural properties of the synthesized powders were investigated through X-ray diffraction (XRD) and field-emission scanning electron microscopy (FESEM), while for the magnetic properties, vibrating sample magnetometer (VSM) measurements were made. XRD patterns revealed characteristic peaks corresponding to spinel Mn-Zn ferrite structures with accompanying secondary phases, such as Fe2O3 and LaFeO3. The initial addition of La3+ into the spinel ferrite system resulted in an initial spike of the lattice parameter and crystallite size before proceeding to decrease as the rare-earth content continues to decrease. FESEM micrographs reveals agglomerated particles with considerable grain size distribution. The magnetic properties, especially the saturation magnetization, Ms, was found to decrease with each increase in La3+ substitution. The research findings revealed the critical influence of the La3+ substitution towards the overall structural and magnetic properties of the Mn-Zn ferrite samples.

Synthesis of MFe2O4 (M=Mg2+, Zn2+, Mn2+) spinel ferrites and their structural, elastic and electron magnetic resonance properties

Structural, elastic and electron magnetic resonance investigations of spinel ferrites with the formula MFe2O4 (M = Mg2+, Zn2+, Mn2+) synthesized by the sol-gel auto-combustion method are reported here. XRD patterns revealed the co-existence of secondary phases along with the ferrite phase. The lattice parameter (8.301 Å, 8.366 Å and 8.434 Å) was found to be varying according to the ionic radii of cations. As determined by scanning electron microscopy (SEM), ZnFe2O4 has a comparatively narrow distribution of grain sizes (1.3–3.8 µm) compared to those in MnFe2O4 (0.8–4.3 µm) and MgFe2O4 (0.3–4.8 µm). The estimated values of average crystallite sizes (17.5 nm, 21.3 nm and 23.3 nm) determined from the X-ray diffraction peaks are considerably less than the average grain sizes (1.3 µm, 1.6 µm and 2.7 µm) estimated from the SEM histograms. The vibrational frequencies in FTIR spectra are in the conformity with the cubic spinel structure and their variation supports the variation of lattice parameter. Equal values of Poission's ratio (0.35) were obtained for the three systems which represent the isotropic behaviour of spinel ferrite systems. The exceptional low value of Lande's g-parameter for ZnFe2O4 indicates the dominance of Fe3+–O–Fe3+ superexchange interaction. Though cation redistribution is possible in the present ferrite systems, the secondary phases existed in these ferrite systems are predominantly influencing the structural, elastic and electron magnetic resonance properties.