Nanocrystalline Ni0.6Zn0.4Fe2O4: A novel semiconducting material for ethanol detection

The structure and crystal phase of the nanocrystalline powders of Ni_1−xZn_xFe₂O₄ (0 ≤ x ≤ 0.5) mixed ferrite, synthesized by ethylene glycol mediated citrate sol-gel method, were characterized by X-ray diffraction and microstructure by transmission electron microscopy. Further studies by Fourier transform infrared spectroscopy were also conducted. Moreover, DC electrical properties of the prepared nanoparticles were studied by DC conductivity measurements. The response of prepared Ni_1−xZn_xFe₂O₄ mixed ferrites to different reducing gases (ethanol, hydrogen sulfide, ammonia, hydrogen and liquefied petroleum gas) was investigated. In particular, Ni_0.6Zn_0.4Fe₂O₄ composition exhibited high response to 100 ppm ethanol gas at 300 °C. Incorporation of palladium further improved the response, selectivity and response time of Ni_0.6Zn_0.4Fe₂O₄ to ethanol gas with the blue shift in the operating temperature by 25 °C.     

Nanocrystalline ferrites NixZn1−xFe2O4: Influence of cation distribution on acidic and gas sensing properties

This work is devoted to a detailed analysis of the interconnection between composition, cation distribution and acidic properties of the surface of nanocrystalline ferrites Ni_xZn_1−xFe₂O₄ obtained by aerosol pyrolysis. The detailed analysis of the Mössbauer spectra allows us to determine the distribution of cations between tetrahedral and octahedral positions in spinel structure. Depending on samples composition, the tetrahedral positions can be occupied by only Fe³⁺ cations (inverse spinel, x≥0.4) or by Fe³⁺ and Zn²⁺ cations (mixed spinel, x=0, 0.2). Increasing the nickel concentration in the ferrite leads to decrease in the number of strong acid centers on the surface. It was found that the decrease in the contribution of strong surface acid sites leads to an increase in sensory sensitivity of the ferrite towards ammonia. For ethanol detection an inverse relationship between sensor signal and surface acidity was observed.     

Structural and magnetic properties of nanocrystalline Ni1−xCuxFe2O4 prepared through oxalates precursors

Spinel ferrites of the composition Ni_1−xCu_xFe₂O₄ (x = 0.0-1.0) have been prepared through the thermal decomposition of their respective impregnated oxalates. The oxalate decomposition process was followed using differential thermal analysis-thermogravimetry techniques (DTA-TG). The synthesized nanocrystallites were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FT-IR). The formation of single-phase ferrite is confirmed by XRD. Tetragonal deformation is observed for samples with composition x ? 0.7. The increase in the lattice parameter with increasing Cu content can be explained based on the relative ionic radius. The TEM image shows spherically non-agglomerated particles with an average crystallite size that agrees well with that obtained from XRD. FT-IR studies show two absorption bands (ν₁ and ν₂) near to 600 and 400 cm⁻¹ for the tetrahedral and octahedral sites, respectively. The hysteresis measurements were done using a vibrating sample magnetometer (VSM). The cation distribution in these compositions is calculated from the magnetization data. With increasing Cu content, the saturation magnetization (M_s) was observed to decrease while the coercivity (H_c) increases. The possible reasons responsible for the composition dependence of the magnetic properties were discussed. The Curie temperature, measured through the temperature dependence of the dc-molar magnetic susceptibility, was found to decrease with increasing Cu content.     

Mechanical and electrical properties of Ni0.65Zn0.35CuxFe2−xO4 ferrite

A series of samples in the system Ni_0.65Zn_0.35Cu_xFe_2?xO₄ (x=0.0, 0.1, 0.2, 0.3, 0.4 and 0.5) were prepared by the usual ceramic technique. X-ray analysis showed that they were cubic spinel (single phase). Young's modulus, the dielectric loss and the change in capacitance under mechanical stress were measured for the samples. Young's modulus decreased with increasing Cu content. This is due to the fact that Cu²⁺ ions entered the lattice substitutionally for Fe³⁺ ions at the octahedral sites, creating lattice vacancies gave rise to lattice strain. The minimum value of the dielectric loss corresponding tox=0.3 may be due to the formation of lattice vacancies retarding the jump frequency to be far from the frequency of the applied a.c. field. The increase in capacitance of the samples with mechanical stress may be explained via the mechanism of dielectric polarization.     

Enzyme mimics of spinel-type CoxNi1−xFe2O4 magnetic nanomaterial for eletroctrocatalytic oxidation of hydrogen peroxide

A series of spinel-type Co_xNi_1−xFe₂O₄ (x = 0, 0.2, 0.4, 0.5, 0.6, 0.8, 1.0) magnetic nanomaterials were solvothermally synthesized as enzyme mimics for the eletroctrocatalytic oxidation of H₂O₂. X-ray diffraction and scanning electron microscope were employed to characterize the composition, structure and morphology of the material. The electrochemical properties of spinel-type Co_xNi_1−xFe₂O₄ with different (Co/Ni) molar ratio toward H₂O₂ oxidation were investigated, and the results demonstrated that Co_0.5Ni_0.5Fe₂O₄ modified carbon paste electrode (Co_0.5Ni_0.5Fe₂O₄/CPE) possessed the best electrocatalytic activity for H₂O₂ oxidation. Under optimum conditions, the calibration curve for H₂O₂ determination on Co_0.5Ni_0.5Fe₂O₄/CPE was linear in a wide range of 1.0 × 10⁻⁸–1.0 × 10⁻³ M with low detection limit of 3.0 × 10⁻⁹ M (S/N = 3). The proposed Co_0.5Ni_0.5Fe₂O₄/CPE was also applied to the determination of H₂O₂ in commercial toothpastes with satisfactory results, indicating that Co_xNi_1−xFe₂O₄ is a promising hydrogen peroxidase mimics for the detection of H₂O₂.     

Microstructure and magnetic properties of electrospun one-dimensional Al-substituted SrFe12O19 nanofibers

SrAl_xFe_12−xO₁₉ (x=0-3.0) nanofibers with diameters about 100 nm have been prepared by electrospinning and subsequent heat treatment. With Al³⁺ ion content ranging from 0 to 3.0, the lattice parameters decrease due to Fe³⁺ ions substituted by smaller Al³⁺ ions and the average grain size calculated by the Scherrer's equation reduces from 65 to 37 nm. The magnetization shows a continuous reduction with the Al content and its value measured at 77 K is higher than at room temperature, which can be explained by Bloch's law. For the coercivity, its value initially increases, reaching a maximum value of 617 (298 K) and 547 kA m⁻¹ (77 K) at x=2.0, and then reduces with the Al content further increase largely arising from the substituted Al³⁺ ion arrangement in different interstitial sites of the strontium ferrite unit cell.     

Preparation and metal binding behavior of poly(4-vinylbenzyl 2-hydroxyethyl) sulfoxide and sulfone

In order to explore the reuse properties of oxidized chelating resin containing sulfur after adsorption, two kinds of novel chelating resins, poly[4-vinylbenzyl-(2-hydroxyethyl)] sulfoxide (PVBSO) and poly[4-vinylbenzyl-(2-hydroxyethyl)] sulfone (PVBSO₂), were synthesized using poly[4-vinylbenzyl-(2-hydroxyethyl)] sulfide (PVBS) as material. Their structures were confirmed by FTIR and XPS. The adsorption properties and mechanism for metal ions such as Au³⁺, Pt⁴⁺, Pd²⁺, Hg²⁺, Cu²⁺, Ni²⁺, Fe³⁺, Pb²⁺, Cd²⁺, and Zn²⁺ were investigated. Experimental results showed that PVBSO had good adsorption and selective properties for Au³⁺, Pd²⁺ and Cu²⁺ when the coexisting ion was Pt⁴⁺, Ni²⁺, Pb²⁺ or Cd²⁺. In the aqueous system containing Cu²⁺ and Pb²⁺ or Cu²⁺ and Cd²⁺, PVBSO₂ only adsorbed Cu²⁺. The selective coefficients of PVBSO and PVBSO₂ were α_Au/Pt = 4.8, α_Au/Pd = 11.8, α_Pd/Pt = 10.9, α_Cu/Ni = 2.5, α_Cu/Cd = 41.2, α_Cu/Pb = ∞, α_Cu/Ni = 3.0, α_Cu/Cd = ∞, α_Cu/Pb = ∞, respectively.     

Structural,textural, morphological,magnetic and electromagnetic study of Cu-doped NiZn ferrite synthesized by pilot-scale combustion for RAM application

The synthesis of the Ni_0.5-xZn_0.5-xCu_2xFe₂O₄ (x = 0; 0.10 and 0.15) ferrite with the differential of pilot-scale production by the combustion reaction method was investigated for RAM application purposes. Combustion temperatures ranging from 682 °C to 738 °C were observed. All ferrites were sintered at 1200 °C for 1 h. A comprehensive study of the influence of substitution with Cu²⁺ in a partial and proportional way to the Ni²⁺ and Zn²⁺ ions, doping mode little reported in the literature, and also of the sintering process over the structural, textural, morphological, magnetic and electromagnetic properties of NiZnCu ferrites was performed. The XRD patterns of the ferrites as synthesized revealed the formation of the cubic structure of the inverse spinel as majoritary phase, and traces of hematite and zinc oxide as segregated phases. After sintering, it was proven the single-phase formation of cubic spinel ferrite structure. The introduction of Cu led to a reduction in the lattice parameter, whose values ranged from 8.337 to 8.385 Å. The EDX results confirm the composition of oxides. The textural and morphological analyses confirmed the densest characteristic, with increase of particle size and reducing of surface area and pore volume after Cu-doping. All ferrites showed characteristics of soft ferrimagnetic material, where the increase in Cu content contributed to a slight reduction in saturation magnetization, whose values were of ~22–29 emu/g for the as synthesized ferrites and ~71–85 emu/g for the sintered ones. The best result of electromagnetic absorption in X-band was presented by the sintered ferrite with 0.3 mol of Cu, reaching an attenuation of 99.8% at 11.5 GHz frequency, thus confirming the efficiency of the pilot-scale combustion synthesis in obtaining a ferrite with great potential for RAM application.     

Sol–gel synthesis of nanocrystalline Zn1−xNixFe2O4 ceramics and its structural,magnetic and dielectric properties

Zn_1?xNi_xFe₂O₄ (0.0 ≤ x ≤ 1.0) nanoparticles are prepared by sol–gel method using urea as a neutralizing agent. The evaluation of XRD patterns and TEM images indicated fine particle nature. The average crystallite size increased from 10 to 24 nm, whereas lattice parameters and density decreased with increasing Ni content (x). Infrared spectra showed characteristic features of spinel structure along with a strong influence of compositional variation. Magnetic measurements reveal a maximum saturation magnetization for Zn_0.5Ni_0.5Fe₂O₄ (x = 0.5); however, reduced value of magnetization is attributed to the canted spin structure and weakening of Fe³⁺(A)–Fe³⁺(B) interactions at the surface of the nanoparticles. Impedance analysis for different electro-active regions are carried out at room temperature with Ni substitution. The existence of different relaxations associated with grain, grain boundaries and electrode effects are discussed with composition. It is suggested that x = 0.5 is an optimal composition in Zn_1?xNi_xFe₂O₄ system with moderate magnetization, colossal resistivity and high value of dielectric constant at low frequency for their possible usage in field sensor applications.     

Hexaferrites and phase relations in the iron-rich part of the system Sr-La-Co-Fe-O

The iron rich part of the system was examined in the temperature range of 1200-1380 °C in air, with focus on the solid solutions of M-type hexaferrites. Samples of suitable compositions were studied by electronprobe microanalysis (EPMA). Substituted Sr-hexaferrites in the system Sr-La-Co-Fe-O do not follow the 1:1 substitution mechanism of La/Co in M-type ferrites. Due to the presence and limited Co²⁺-incorporation Fe³⁺-ions are reduced to Fe²⁺ within the crystal lattice to obtain charge balance. In all examined M-type ferrites divalent iron is formed, even at 1200 °C. The substitution principle Sr²⁺+Fe³⁺↔La³⁺+(Fe²⁺, Co²⁺) yields to the general substitution formula for the M-type hexaferrite Sr²⁺_1-xLa³⁺_xFe²⁺_x-yCo²⁺_yFe³⁺_12-xO¹⁹ (0≤x≤1 and 0≤y≤x). In addition Sr/La-perovskite_SS (_SS=solid solution), Co/Fe-spinel_SS, hematite and magnetite are formed. Sr-hexaferrite exhibits at 1200 °C a limited solid solution with small amounts of Fe²⁺ (SrFe₁₂O₁₉↔Sr_0.3La_0.7Co_0.5Fe²⁺_0.2Fe_11.3O₁₉). At 1300 and 1380 °C a continuous solid solution series of the M-type hexaferrite is stable. SrFe₁₂O₁₉ and LaCo_0.4Fe²⁺_0.6Fe₁₁O₁₉ are the end members at 1300 °C. The maximum Fe²⁺O content is about 13 mol% in the M-type ferrite at 1380 °C (LaCo_0.1Fe²⁺_0.9Fe₁₁O₁₉).     

Fluctuation in occupancy of Cu2+ ions in Zn- and Cd-substituted Cu-ferrites

Mössbauer effect technique has been used for the comparative study of Cu_1?x Zn _x Fe₂O₄ and Cu_1?x Cd _x Fe₂O₄ ( _x = 0.0?1.0) ferrites. Both Zn²⁺ and Cd²⁺ cations are divalent, non-magnetic ions with different ionic radii. With the substitution of these non-magnetic cations the average internal magnetic field decreases and paramagnetic behavior is dominated at x = 0.7 in both series. It is observed that the occupancy of Cu²⁺ ions for tetrahedral site is not constant for all compositions but fluctuate between 8–15%. It is also found that Cu²⁺ ions have more preference for tetrahedral site in Cu-Zn system as compared to the Cu-Cd system. Zn²⁺ and Cd²⁺ both ions occupy tetrahedral site completely and form normal spinels for x = 1.0.     

Sintering behaviour of the spinel ferrite system Ni0.65Zn0.35Fe2−xCuxO4

A series of samples of the system Ni_0.65Zn_0.35CuxFe_2–xO₄ (x=0, 0.1, 0.2, 0.3, 0.4, 0.5 and 0.6) are prepared by the usual ceramic technique. X-ray analysis shows that they are cubic spinel (single phase). The lattice parameter, theoretical density (D _x), bulk density (D) and the porosity (P) are measured for the samples. The vacancy concentration of oxygen is an important parameter in the sintering process of spinel ferrites. The decrease in the population of Fe³⁺ ion in the octahedral sites with the introduction of Cu²⁺ results in the decrease of lattice parameter. The DTA tracing shows a strong exothermic peak at 90°C.

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Zusammenfassung Mittels herkömmlicher keramikchemischer Verfahren wurde eine Reihe von Proben des Systemes Ni_0.65Zn_0.35Cu_xFe_2–xO₄ (x=0, 0.1, 0.2, 0.3, 0.4, 0.5 und 0.6) hergestellt. Röntgendiffraktionsanalyse zeigt kubisches Spinell (eine Phase). Es wurden die Gitterkonstanten, die theoretische DichteDx, die RaumdichteD und die PorositätP dieser Proben gemessen. Die Gitterleerstellenkonzentration von Sauerstoff ist ein wichtiger Parameter beim Sintern von Spinellferriten. Die Abnahme der Besetzung mit Fe³⁺-Ionen bei der Einbringung von Cu²⁺ führt zu kleineren Gitterkonstanten. DTA-Kurven zeigen einen starken exothermen Peak bei 90°C.

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The measurements were carried out at the Solid-state Physics Laboratory, Faculty of Science, Tanta University.

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The authors are grateful to the technical assistance of the Central Laboratory of Tanta and Manoufia University for X-ray and DTA facilities.     

Effect of heat treatment on particle growth and magnetic properties of electrospun Sr<Subscript>0.8</Subscript>La<Subscript>0.2</Subscript>Zn<Subscript>0.2</Subscript>Fe<Subscript>11.8</Subscript>O<Subscript>19</Subscript> nanofibers

Sr_0.8La_0.2Zn_0.2Fe_11.8O₁₉/poly(vinyl pyrrolidone) (PVP) composite fiber precursors were prepared by the sol–gel assisted electrospinning. Subsequently, the M-type ferrite Sr_0.8La_0.2Zn_0.2Fe_11.8O₁₉ nanofibers with diameters about 120 nm were obtained by calcination of these precursors at different heat treatment conditions. The precursor and resultant Sr_0.8La_0.2Zn_0.2Fe_11.8O₁₉ nanofibers were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectrometer and vibrating sample magnetometer. With the calcination temperature increased up to 1,000 °C for 2 h or the holding time prolonged to 12 h at 900 °C, the Sr_0.8La_0.2Zn_0.2Fe_11.8O₁₉ particles gradually grow into a hexagonal elongated plate-like morphology due to the dimensional control along the nanofiber length. These elongated plate-like particles will be linked one by one to form the nanofiber with a necklace-like morphology. The magnetic properties of the Sr_0.8La_0.2Zn_0.2Fe_11.8O₁₉ nanofibers are closely related to grain sizes, impurities and defects in the ferrite, which are influenced by the calcination temperature, holding time and heating rate. After calcined at 900 °C for 12 h with a heating rate of 3 °C/min, the optimized magnetic properties are achieved with the specific saturation magnetization 75.0 A m² kg⁻¹ and coercivity 426.3 kA m⁻¹ for the Sr_0.8La_0.2Zn_0.2Fe_11.8O₁₉ nanofibers.     

Thermal conductivity of the ferrites Ni0.65Zn0.35CuxFe2−xO4

A series of samples of the type Ni_0.65Zn_0.35Cu_xFe_2?xO₄ (x=0, 0.1, 0.2, 0.3, 0.4 and 0.5) were prepared by a ceramic technique. The existence of a single phase was confirmed by X-ray studies. The thermal conductivity and specific heat were measured at 53°C. The thermal conductivity had a minimum value atx=0.3, due to the maximum porosity at this composition. The phonon frequency was estimated to have an optimum value at x=0.3, due to the increase in phonon scattering.     

Synthesis and neel temperature determination of ferrites from the CuO−ZnO−Fe2O3 system

Conditions were established and individual and mixed ferrites with the general formula Cu_xZn_1?xFe₂O₄ (x=0; 0.1; 0.2; 0.3; 0.4; 0.5; 0.6; 0.7; 0.8; 1.0) were synthesized from the CuO?ZnO?Fe₂O₃ system. X-ray phase analysis, Mössbauer spectroscopy and microscopic examinations revealed that the obtained ferrites are monophase samples. A magnetic device was attached to the Q-Derivatograph (MOM, Hungary) and successfully used for sample investigation in a magnetic field, and in particular for Curie (Neel) temperature determination. The ferrite composition and the thermal treatment conditions were shown to correlate with the Neel temperature of the synthesized ferrites.     

Structural,morphological and magnetic properties of nano-crystalline zinc substituted cobalt ferrite system

Nano-crystalline zinc-substituted cobalt ferrite powders, Co_1−xZn_xFe₂O₄ (x = 0, 0.25, 0.5, 0.75 and 1), have been synthesized by the combustion route. The structural, morphological and magnetic properties of the products were determined and characterized in detail by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX) and vibrating sample magnetometer (VSM). X-ray analysis showed that the samples were cubic spinel. The increase in zinc concentration resulted in an increase in the lattice constant, unit cell volume, X-ray density, ionic radii, the distance between the magnetic ions and bond lengths on tetrahedral sites and octahedral sites of cubic spinel structure. Opposite behavior was observed for the average crystallite size of the as synthesized solids. The variation of saturation magnetization (M_s) value of the samples was studied. The maximum saturation magnetization value of the Co_o.25Zn_0.75Fe₂O₄ sample reached 76.87 emu/g. The high saturation magnetization of these samples suggests that this method is suitable for preparing high-quality nano-crystalline magnetic ferrites for practical applications.     

H2S sensing properties of nanocrystalline Sr2FeO.6NiO.4MoO6 thick film prepared by sol-gel citrate method

Nanocrystalline Sr₂FeMoO₆ (SFMO) belonging to the group of double perovskite oxides, was prepared by the sol-gel citrate method. The structural and microstructural characterization has been carried out with the help of X-ray diffraction (XRD) and transmission electron microscopy (TEM), respectively. XRD of Sr₂Fe_1−xNi_xMoO₆ (SFNMO) shows the formation of solid solution with average grain size of about 40 nm. A comparative study of gas sensing behaviour of Sr₂FeMoO₆ and Sr₂Fe_1−xNi_xMoO₆ with reducing gases like hydrogen sulfide (H₂S), liquid petroleum gas (LPG), hydrogen (H₂), ethanol (C₂H₅OH) and carbon monoxide (CO) were also discussed. The sensitivity is calculated by measuring the change the resistance of the sensor material in the presence of gas. Among the different composition of x (x = 0.2, 0.3, 0.4, 0.5), Sr₂Fe_0.6Ni_0.4MoO₆ (x = 0.4) shows better response to H₂S gas at 260 °C. Incorporation of palladium (Pd) improves the gas response, selectivity, response time and reduced the operating temperature from 260 to 220 °C for H₂S gas.     

The influence of Ni2+ lons on the distribution of Mg2+ and Cu2+ lons in spinel ferrites

Cation distribution in quenched and furnace-cooled samples of composition Ni_xM_1?xFe₂O₄ (where M is either Mg²⁺ or Cu²⁺) has been studied through magnetization measurements. It has been found that cation distribution in these mixed ferrites cannot be predicted by site preference energies. In magnesium-nickel ferrites, cation distribution is controlled by heat treatment up to x = 0.5, beyond which the effect of heat treatment diminishes. Addition of Ni²⁺ ions in copper ferrite reduces the diffusibility of Cu²⁺ ions and the distribution tends toward inverse spinel in the high-nickel region.     

Mechanism of NiZn ferrite formation

The regularities in the change of character of the ferrite formation process as a function of Ni_1?xZn_xFe₂O₄ solid solution and of the degree of zinc oxide saturation of the Ni_1?xZn_xO solid solution (x = 0.14; 0.29; 0.43) are established in the temperature range 1220–1305°C. It is shown that in the reaction zone of interacting NiO, (Ni, ZnO), or ZnO with Fe₂O₃ the ferrite phase crystallizes only on iron oxide. The distribution of the Fe, Ni, and Zn concentrations over the reaction layer thickness using electron probe and X-ray spectrum analysis is obtained. The interdiffusion coefficients over the investigated temperature range calculated in the (Ni, Zn, Fe)O and ferrite phases change from (0.8 – 7.0) × 10^?9 to (1.0 – 12.0) × 10^?10 cm²/sec, respectively. The interaction of (Ni, Zn)O with Fe₂O₃ takes place by the mechanism of interaction of interdiffusion of Fe³⁺, Fe²⁺ and Ni²⁺, Zn²⁺ along with a current of Zn²⁺ ions and electrons or oxygen ions directed to the $\text{ferrite}\text{Fe}{}_2\text{O}{}_3$ interface.     

Cu–Ce substituted cobalt nano ferrite - Structural,morphological, and magnetic behavior prepared by sol-gel auto-combustion

Sol-gel auto-combustion synthesized Co_1-xCu_xFe_2-yCe_yO₄ (x = 0.0, 0.25, 0.5 and 0.75; y = 0.0, 0.03, 0.06, and 0.09), Cu–Ce substituted Co ferrite nanopowders. Investigations have been done on how Cu–Ce substitution affects the structural and magnetic characteristics. The Cu–Ce substitution variation effect on structural and magnetic properties is studied with X-ray diffraction (XRD), Field effect scanning electron microscopy (FESEM), Fourier transform infrared spectroscopy (FTIR), and Vibrating sample magnetometer (VSM). The XRD was used to identify the crystal phase, and the role of Cu–Ce substituted for Co indicates how it formed. There is no change in the crystal structure, and no additional characteristic peak linked to Cu²⁺ and Ce³⁺ ions substitution was found in the XRD. The powder was sintered at 1100 °C. The crystallite sizes were found in between 33 and 62 nm. Increasing the Cu–Ce content decreases the lattice constant and is found between 8.4044 and 8.3309 Å. The FESEM images were used to analyze the nanostructural properties. The range of 110–128 nm is the value of average grain size. Two vibrational bands can be seen in FTIR spectra at about 600 cm⁻¹ (v₁) and 400 cm⁻¹ (v₂). They are attributed to the spinel lattices A and B sites, respectively. The tetrahedral site has a greater vibrational frequency of 566.09 cm^−1, while the octahedral site has a lower vibrational frequency of 420.09 cm⁻¹. FTIR spectra show the tetrahedral stretching peaks shifting towards lower frequencies with increasing Cu²⁺ and Ce³⁺ ions content. At ambient temperature, the magnetic properties of Cu–Ce substituted cobalt ferrites revealed a strong hysteresis loop. There was a decrease in magnetic saturation and an increase in coercivity.