Morphology-controlled therapeutic activity of cerium oxide nanoparticles for mild traumatic brain injury

The design and optimization of nanostructures with unique morphologies and properties are at the forefront of biomedical nanotechnology. Cerium oxides are widely used to investigate the effect of morphology on performance. However, elucidating the morphology–activity relationship of cerium oxide nanocrystals in biomedical applications remains challenging. Herein, the therapeutic effects of cerium oxide nanoparticles with different morphologies: cerium oxide nanorods with two different aspect ratios (CeO_x NRs_A and CeO_x NRs_B), cerium oxide nanopolyhedra (CeO_x NPs), and cerium oxide nanocubes (CeO_x NCs) are investigated in in vivo and in vitro mild traumatic brain injury (TBI) models. Cerium oxide nanoparticles inhibit oxidative stress and inflammation after mild TBI, alleviating cognitive impairment; furthermore, the therapeutic effect is significantly affected by their morphology. Owing to the higher Ce³⁺/Ce⁴⁺ ratio, exposure of more active crystal surfaces, and greater number of exposed oxygen vacancies, CeO_x NRs show better activity than CeO_x NPs and CeO_x NCs for mild TBI. Among the two investigated types of cerium oxide nanorods, CeO_x NRs_A, with a higher Ce³⁺/Ce⁴⁺ ratio on the surface, appear to spread better than CeO_x NRs_B in the injured lesions. The factors causing morphology-controlled biomedical performance, such as Ce³⁺/Ce⁴⁺ molar ratio, surface area, and aspect ratio, are discussed.     

Ce–Zr-Sm ternary oxides synthesized via a template free urea-hydrothermal method

Nano-crystalline Ce_0.9Zr_0.1-xSm_xO_2-δ (0 ≤ x ≤ 0.10) mixed oxides were synthesized for the first time by a urea-hydrothermal method without the use of template or structure directing agents. The use of a high molar ratio of urea to metal cations and temperature reaction ensures the formation of a single-phase homogeneous ternary solid solution. The (NH₄)₂Ce(NO₃)₆ precursor, in a greater proportion, together with urea acts as a structure directing agent towards the completion of a self-assembly shuttle to dumbbells to sphere sequence. The analysis of the obtained morphologies has demonstrated that the physicochemical nature of the doping precursor in solution has a strong influence on the final morphology without losing morphological control. Thus, the ZrO(NO₃)₂ precursor favors the formation of cauliflower-type particles whereas Sm(NO₃)₃ favors the formation of spheres. As a result, the morphology of the samples evolves from cauliflowers to spheres as Sm content increases in the mixed oxides, with a great effect on the high specific surface area (80–115 m².g^?1) and total pore volume (0.109–0.315 cm³.g^?1) obtained in all cases. Solids reduce in three stages reaching high reduction percentages (≈50%).     

Ceria nanocube with reactive {100} exposure planes: Simple and controllable synthesis under moderate conditions

{100} planes of CeO₂ are unstable polar surfaces and important to enhance the oxygen storage capacity. However, a convenient method is still needed for the synthesis of ceria nanocubes which expose six {100} facets. Here, a new and facile synthesis strategy has been developed to synthesize single-crystalline nanocubes of CeO₂. According to transmission electron microscopy, these nanocubes are enclosed by six {100} facets. It is proved that in the synthesis process, the acetate radical ions would adsorb on the positive charged Ce(OH)₃ formed from the reaction of Ce³⁺ and ammonia, then partially inhibit the redox between Ce(OH)₃ and NO₃⁻ and protect the {100} facets during crystal growth. Meanwhile, the Ce⁴⁺ ions would act as crystal seeds to facilitate the formation of single crystals. Both of the addition of Ce⁴⁺ ions and CH₃COO⁻ ions are necessary for the synthesis of monocrystal ceria nanocubes. Throughout the synthesis process, it is moderate reaction conditions that the pressure is atmospheric pressure and temperature is no higher than 80 °C.     

Nanostructured co-precipitated Ce0.9Ln0.1O2 (Ln = La,Pr, Sm,Nd, Gd,Tb, Dy,or Er) for thermochemical conversion of CO2

The influence of lanthanide metal cations doped into the CeO₂ crystal structure (to form Ce_0.9Ln_0.1O₂; Ln = La, Pr, Nd, Sm, Gd, Tb, Dy, or Er) on thermochemical reduction and the CO₂ splitting ability of Ce_0.9Ln_0.1O₂ is scrutinized using thermogravimetric analysis. Ce_0.9Ln_0.1O₂ redox materials are effectively synthesized by co-precipitation of hydroxides. As-synthesized Ce_0.9Ln_0.1O₂ redox materials are further characterized based on their phase composition, crystallite size, surface area, and morphology using powder X-ray diffraction, Brunauer-Emmett-Teller surface area analysis, and scanning electron microscopy. The thermal reduction and CO₂ splitting aptitude of Ce_0.9Ln_0.1O₂ redox materials are examined by performing 10 consecutive thermochemical cycles. The results imply that insertion of Sm³⁺, Er³⁺, Tb³⁺, Dy³⁺, and La⁺³ in place of Ce⁴⁺ in the fluorite crystal structure of CeO₂ (forming Ce_0.9Ln_0.1O₂) enhances the O₂ liberation by 22.5, 14.6, 12.6, 5.85, and 2.96 μmol O₂/g·cycle, respectively. Besides, CeLa is observed to be more active towards the CO₂ splitting reaction than CeO₂ and the other Ce_0.9Ln_0.1O₂ redox materials investigated in this study.     

Defect induced magnetic transition in Co doped CeO2 sputtered thin films

Cobalt-doped cerium dioxide thin films exhibit room temperature ferromagnetism due to high oxygen mobility in doped CeO₂ lattice. CeO₂ is an excellent doping matrix as there is a possibility of it losing oxygen while retaining its structure. This leads to increased oxygen mobility within the fluorite CeO₂ lattice, leading to formation of Ce³⁺ and Ce⁴⁺ species. Magnetic ceria materials are important in several applications from magnetic data storage devices to magnetically recoverable catalysts. In this paper, the room temperature ferromagnetism of rf sputtered Co doped CeO₂ thin films is reported whereas undoped CeO₂ thin films exhibit paramagnetic behavior. The ferromagnetic properties of the Co doped films were explained based on oxygen vacancies created by Co ions in Ce sites. This is further supported by X-ray photoelectron spectroscopy (XPS), photoluminescence (PL) and Raman. Change in surface morphology due to Co doping of the samples were analyzed using atomic force microscopy (AFM).     

Preparation of oxygen vacancy-controllable CeO2 by electrotransformation of a CeCl3 solution and its oxidation mechanism

CeO₂ was successfully prepared by electrotransformation of CeCl₃ solution in previous work. In this work, the oxidation mechanism of Ce³⁺ was determined by cyclic voltammetry and a potential-pH diagram, which indicated that Ce³⁺ was oxidized by oxygen during the electrotransformation, and the important role of the oxygen content in solution was confirmed. Thus, the influence of atmosphere (air/argon/oxygen) on CeO₂ preparation was investigated by adjusting the gas type and flow rate. XRD patterns demonstrated the cubic fluorite structure and grain size of CeO₂. With an increase in the gas flow rate, the grain size decreased, but the particle size increased. This result indicated that the smaller grains contained more lattice defects and higher surface energy, so the grains preferred to agglomerate together, forming larger particles. XPS spectra proved that Ce³⁺ and Ce⁴⁺ both existed in the CeO₂ samples. Raman scattering revealed that more oxygen vacancies could be produced with an argon atmosphere and high gas flow.     

Morphology Tunable Self‐Assembled Sr2P2O7:Ce3+, Mn2+ Phosphor and Luminescence Properties

Uniform orange‐to‐red spherical phosphors of Sr₂P₂O₇:Ce³⁺, Mn²⁺ have been synthesized by the co‐precipitation method and characterized by X‐ray powder diffraction, scanning electron microscopy, and photoluminescence spectroscopy. The results indicate that the morphology, size, and photoluminescence properties of Sr₂P₂O₇:Ce³⁺, Mn²⁺ phosphors can be effectively controlled by the reaction and the sintering temperatures. Energy transfer from Ce³⁺ to Mn²⁺ in Sr₂P₂O₇ phosphor was observed from photoluminescence spectra of Sr₂P₂O₇:Ce³⁺, Sr₂P₂O₇:Mn²⁺, and Sr₂P₂O₇:Ce³⁺, Mn²⁺. Moreover, based on a self‐assembly process, a possible formation mechanism for the spherical phosphors is proposed. The uniform phosphor spheres obtained in this work exhibit great potential for high‐resolution display devices such as light emitting diodes.     

Structure-activity Relation of Fe2O3–CeO2 Composite Catalysts in CO Oxidation

A series of Fe₂O₃–CeO₂ composite catalysts were synthesized by coprecipitation and characterized by X-ray diffraction (XRD), BET surface area measurement, Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). Their catalytic activities in CO oxidation were also tested. The Fe₂O₃–CeO₂ composites with an Fe molar percentage below 0.3 form solid solutions with the CeO₂ cubic fluorite structure, in which the doped Fe³⁺ initially substitutes Ce⁴⁺ in fluorite cubic CeO₂, but then mostly locate in the interstitial sites after a critical concentration of doped Fe³⁺. With an Fe molar percentage between 0.3 and 0.95, the Fe₂O₃–CeO₂ composites are mixed oxides of the cubic fluorite CeO₂ solid solution and the hematite Fe₂O₃. XPS results indicate that CeO₂ is enriched in the surface region of Fe₂O₃–CeO₂ composites. The Fe₂O₃–CeO₂ composites have much higher catalytic activities in CO oxidation than the individual pure CeO₂ and Fe₂O₃, and the Fe_0.1Ce_0.9 composite shows the best catalytic performance. The structure-activity relation of the Fe₂O₃–CeO₂ composites in CO oxidation is discussed in terms of the formation of solid solution and surface oxygen vacancies. Our results demonstrate a proportional relation between the catalytic activity of cubic CeO₂-like solid solutions and their density of oxygen vacancies, which directly proves the formation of oxygen vacancies as the key step in CO oxidation over oxide catalysts.     

Absorption Spectra and Bioactivity Behavior of Gamma Irradiated CeO2-Doped Bioglasses

The synthesis and characterization of some bioglasses based on Hench’s Bioglass® 45S5 with additions of CeO₂ (1.0, 2.0, or 3.0%) have been carried out. Two objectives have been focused upon; first, the effect of successive ionizing gamma irradiation on the undoped and CeO₂-doped bioglass samples has been evaluated with the aim of justifying the role of the rare earth oxide CeO₂ on gamma irradiation. The second objective was directed to test the bioactivity of such prepared CeO₂-doped samples after soaking for 1 month in a simulated body fluid at 37 °C. The results indicate that the additions of CeO₂ suppress, to a marked extent, the generation of radiation induced defects especially in the visible region. The bioactivity results show that the studied CeO₂-doped bioglass samples gave rise to a calcium phosphate surface layer upon immersion in a simulated body fluid for 1 month at 37 °C and the bioactivity extent was almost identical in the CeO₂ doping interval limit (1?→?3% CeO₂) to that of the undoped base Hench’s Bioglass. The presence of both Ce³⁺ and Ce⁴⁺ ions were confirmed by optical absorption spectra. Electron spin resonance (ESR) studies of gamma irradiated CeO₂-doped glasses indicate and confirm the dominance of Ce⁴⁺ in the bioglass compositions and its transformation to Ce³⁺ by high gamma irradiation.     

Optical Investigation of Ce3+‐Activated Borogermanate Glass Induced by Substitution of BaF2 for BaO

Transparent and colorless CeO₂‐activated borogermanate glasses, with the nominal molar composition of 25B₂O₃–40GeO₂–14Gd₂O₃–1CeO₂–(20?x) BaO–xBaF₂ (x = 0, 2.5, 5, 10, 15 and 20), were synthesized by a melt‐quenching method in air. Their optical investigation on the transmittance, photoluminescence (excitation and emission spectra), the luminescence decay curves, as well as the temperature‐dependent Ce³⁺ emission are studied systematically with the gradual substitution of BaF₂ for BaO. The room‐temperature photoluminescence results reveal that the emission intensity can be improved by about 2.5 times with the full substitution of BaF₂ for BaO. The blue shift of the cut‐off edge, excitation and emission spectra of Ce³⁺‐activated borogermanate glass, and the emission intensity of Ce³⁺ ions as a function of temperature range in 80–500 K are also discussed.     

The influence of chelating agents on cerium oxide decorated on graphite synthesized by the hydrothermal route

Morphology features of cerium oxide nanoparticles, such as size and agglomeration, are important as a coating that improves corrosion resistance and as reinforcement in mechanical applications. In this work, the influence of two heat treatments (160° and 190 °C) in combination with three different chelating agents in the preparation of CeO₂ and CeO₂ decorated on graphite (CeO₂_Gr) nanoparticles is studied. The novelty of this work is that CeO₂_Gr was successfully prepared using the hydrothermal method. All the samples evaluated by X-ray diffraction exhibit a single fluorite-type structure in the cubic phase and Fm3m space group. The spherical harmonics method using the Fullprof Suite program was used to determine the average crystallite sizes, which were 9 nm for CeO₂ and 7 nm for CeO₂_Gr. Transmission electron micrographs for the prepared samples with citric acid showed non-agglomerate particles with homogeneous particle sizes and a quasi-spherical shape distribution. Raman spectra show a band centre at 600 cm^-1 associated with the presence of Frenkel-type oxygen vacancies that induced the reduction of Ce⁴⁺ to Ce³⁺. The analysis of X-ray photoelectron spectra corroborates the coexistence of Ce³⁺ and Ce⁴⁺ species for CeO₂ and CeO₂_Gr nanoparticles. This work forms new perspectives in the development of CeO₂ decorated on graphite prepared by the hydrothermal method to obtain composites not only for sensing applications and wastewater treatment but also for corrosion resistance and reinforcement materials.     

Fused silica with sub-angstrom roughness and minimal surface defects polished by ultrafine nano-CeO2

Surface quality of fused silica, particularly surface defect and surface roughness, is a key factor affecting the performance of high-power laser and short-wave optical instrument, and so on. Herein, the super smooth surface of fused silica with roughness of sub-angstrom level and exceedingly few submicron defects was achieved by using ultrafine nano-CeO₂ with primary particle size less than 4 nm, low secondary particle agglomeration strength, and high Ce³⁺ concentration. Furthermore, CeO₂ involve in polishing process in the form of primary particle was certified by experiment. Moreover, the cause for the generation of submicron defects on fused silica surface was investigated for the first time from the perspective of secondary particle agglomeration strength of CeO₂. The concentration of Ce³⁺ in CeO₂ was characterized by the redshift of the band-gap energy, and the analysis of material removal rate (MRR) and contact angle of polished fused silica shows that Ce³⁺ enhances MRR through increasing the silanol group on fused silica.     

Solar Thermal Hydrogen Production from Water over Modified CeO2 Materials

A series of cerium oxide based materials for hydrogen production from water was studied by temperature-programmed reduction, X-ray diffraction and X-ray photoelectron spectroscopy (XPS) in addition to thermal reactions with water vapour. The addition of uranium ions into CeO₂, making mixed oxides Ce _x U_1?x O₂, resulted in noticeable modification of the reduction properties of CeO₂; with the main observations being the decrease in reduction temperature and the increase of hydrogen consumption when compared to CeO₂ alone. XPS U4f of the as prepared Ce_0.5U_0.5O₂ showed the presence of large amounts of U⁶⁺ cations at 380.9 eV in addition to the U⁴⁺ cations at 379.9 eV; the ratio U⁴⁺ to U⁶⁺ cations was found equal to 0.35. XPS Ce3d showed, on the contrary, considerable amount of Ce³⁺ cations with an estimated ratio of Ce³⁺ to Ce⁴⁺ = ca. 0.5. Ar-ions sputtering results in decreasing the U⁶⁺ contribution and a dramatic increase of the Ce³⁺ contribution. The decrease of U⁶⁺ cations was, however, not mirrored by the increase in Ce³⁺ cations. After five minutes of Ar ions sputtering (1 kV, 10 mA) the surface and near surface Ce3d line shapes looked closer to those of Ce₂O₃ with prominent Ce3d_5/2 and Ce3d_3/2 lines at 885.6 and 904.0 eV attributed to v′ and u′, respectively. The Ce _x U_1?x O₂ series was tested for hydrogen production from water (where x = 0, 0.25, 0.5, 0.75 and 1). All uranium containing oxides had higher activity than CeO₂ or UO₂ alone. Ce_0.75U_0.25O₂ was found to have the highest activity in the studied series; about one order of magnitude higher than that of CeO₂ alone at the same temperature. The reason for the enhanced activity is linked to the ease by which oxygen ions are removed from the oxide materials.     

Chemical Removal of CeO2 Segregated on the Surface of CeO2–ZrO2 Binary Oxides for Improvement of OSC

A chemical treatment to remove residual CeO₂ phase on CeO₂–ZrO₂ (CZ) solid solution was carried out. A CZ was treated by H₂O₂ for the reduction of Ce⁴⁺ to Ce³⁺ and then HNO₃ for the dissolution of Ce³⁺ compounds (H–CZ). H₂-TPR, TEM-EDX and XPS analyses revealed the removal of CeO₂ phase and the homogeneous distribution of Ce species. About 20% improvement in oxygen storage capacity (OSC) of H–CZ was confirmed at 773 K by the weight measurements under H₂/N₂ and air atmospheres, indicating that the HNO₃/H₂O₂ treatment was effective to avoid the deterioration of the OSC by segregated CeO₂ on the CZ binary oxides.     

The photocatalytic oxidation of water to O2 over pure CeO2, WO3, and TiO2 using Fe3+ and Ce4+ as electron acceptors

We report here the results from a study on the photocatalytic decomposition of water to oxygen over pure WO₃, CeO₂, and TiO₂. It has been demonstrated that Fe_aq³⁺ and Ce_aq⁴⁺ species are efficient electron acceptors during the photoproduction of O₂ over a variety of oxides, even at very low concentrations. The O₂ yield was found to depend on the type and surface activity of the cation used as an electron acceptor, and the salt counter anion. While Ce_aq⁴⁺ gives slightly higher initial O₂ rates, Fe_aq³⁺ tends to give higher long-term O₂ yields. The O₂ yield was found to be mainly sensitive to the intrinsic properties of a given material, such as the type of the oxide used and its physicochemical characteristics, e.g. crystal structure and level of crystallinity. For the powders tested, O₂ production was independent of the BET surface area and the activity does not correlate directly with the onset of light absorption of the powders. With a light having λ≥330 nm, O₂ production activity decreased in the order TiO₂-rutile>TiO₂-anatase>WO₃>CeO₂⪢amorphous TiO₂, whereas with a light having λ≥420 nm, it decreased in the order WO₃>TiO₂>CeO₂. Small amounts of Sn on TiO₂-rutile markedly improved its activity. In addition, the O₂ yield strongly depended on the concentration of the electron acceptor and the pH of the suspension. During the reaction, small amounts of hydrogen were also produced. The reaction pathways for electron scavenging by Ce_aq⁴⁺ and Fe_aq³⁺, and the process leading to O₂ evolution will be discussed.     

Catalytic Efficiency of Ceria–Zirconia and Ceria–Hafnia Nanocomposite Oxides for Soot Oxidation

The catalytic oxidation of soot particulates has been investigated over CeO₂, CeO₂–ZrO₂ and CeO₂–HfO₂ nanocomposite oxides. These oxides were synthesized by a modified precipitation method employing dilute aqueous ammonia solution. The prepared catalysts were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), Raman spectroscopy, UV-Vis diffuse reflectance spectroscopy (UV-Vis DRS) and BET surface area methods. The soot oxidation has been evaluated by a thermogravimetric method under ‘tight contact’ conditions. The XRD results revealed formation of cubic CeO₂, Ce_0.75Zr_0.25O₂ and Ce_0.8Hf_0.2O₂ phases in case of CeO₂, CeO₂–ZrO₂ and CeO₂–HfO₂ samples, respectively. TEM studies confirm the nanosized nature of the catalysts. Raman measurements suggest the presence of oxygen vacancies, lattice defects and oxide ion displacement from normal ceria lattice positions. UV-Vis DRS studies show presence of charge transfer transitions Ce³⁺←O^2? and Ce⁴⁺←O^2? respectively. The catalytic activity studies suggest that the oxidation of soot could be enhanced by incorporation of Zr⁴⁺ and Hf⁴⁺ into the CeO₂ lattice. The CeO₂–HfO₂ combination catalyst exhibited better activity than the CeO₂–ZrO₂. The observed high activity has been related to the nanosized nature of the composite oxides and the oxygen vacancy created in the crystal lattice.     

Investigation of La3+-modified Al2O3supported CeO2

X-ray photoelectron spectroscopy measurements indicate that the Ce³⁺ fraction in Al₂O₃-supported CeO₂ can be decreased by the incorporation of La³⁺. If La³⁺ is incorporated into the Al₂O₃ before CeO₂ is added, a higher CeO₂ dispersion and a greater range of reversible reducibility of the CeO₂ may also be obtained. These changes offer potential for improvement in the oxygen storage capacity provided by CeO₂ in three-way catalysts.     

TiO2 Supported Nano-Au Catalysts Prepared Via Solvated Metal Atom Impregnation for Low–Temperature CO Oxidation

The Ce _x Ti_1?x O₂ mixed oxides at different mole ratios (x=0.1–1.0) were prepared by co-precipitation of TiCl₄ and Ce(NO₃)₃. The structural and reductive properties of the Ce _x Ti_{1? x} O₂ were affected by calcination temperature. At x=0.1–0.3, CeTi₂O₆ phase was formed and mainly as amorphous after calcination at 650°C. At x=0.3, only CeTi₂O₆ was formed after calcination at 750°C and CeTi₂O₆ crystallized completely after calcination at 800°C. TPR analyses showed that the amount of H₂ consumption by Ce _x Ti_1?xO₂ (650°C) (except x=0.1) was greater than that by single CeO₂, and the valence of CeO₂was the lowest (+3.18) at x=0.3. CuO/Ce_0.3Ti_0.7O₂ was prepared by the impregnation method and catalytic properties were examined by means of a GC micro-reactor NO+CO reaction system, BET, TPR, XRD, XPS and NO-TPD. It was found that CuO/Ce_0.3Ti_0.7O₂ calcined at 650°C had the highest activity in NO+CO reaction with 100% NO conversion at reaction temperature of 300°C, and at 650°C Ce_0.3Ti_0.7O₂just began to crystallize. The catalytic activities were largely affected by the pre-treatment conditions. At low reduction temperature (100°C), CuO species was difficult to reduce. When high degree of reductions took place, both CuO species and Ce_0.3Ti_0.7O₂ reduced and thus a part of CuO species on the support surface would be covered. The XPS and NO-TPD analyses showed that CuO/Ce_0.3Ti_0.7O₂ had four NO absorption centers (Cu⁺, Cu²⁺(I), Cu²⁺(II) and Ce³⁺). The CuO species involving in NO+CO reaction included Cu²⁺(I) and Cu⁺, and CeO₂ species (Ce³⁺ and Ce⁴⁺).     

In-situ XPS Study on the Reducibility of Pd-Promoted Cu/CeO2 Catalysts for the Oxygen-assisted Water-gas-shift Reaction

Cu/CeO₂, Pd/CeO₂, and CuPd/CeO₂ catalysts were prepared and their reduction followed by in-situ XPS in order to explore promoter and support interactions in a bimetallic CuPd/CeO₂ catalyst effective for the oxygen-assisted water-gas-shift (OWGS) reaction. Mutual interactions between Cu, Pd, and CeO₂ components all affect the reduction process. Addition of only 1 wt% Pd to 30 wt% Cu/CeO₂ greatly enhances the reducibility of both dispersed CuO and ceria support. In-vacuo reduction (inside XPS chamber) up to 400 °C results in a continuous growth of metallic copper and Ce³⁺ surface species, although higher temperatures results in support reoxidation. Supported copper in turn destabilizes metallic palladium metal with respect to PdO, this mutual perturbation indicating a strong intimate interaction between the Cu–Pd components. Despite its lower intrinsic reactivity towards OWGS, palladium addition at only 1 wt% loading significantly improved CO conversion in OWGS reaction over a monometallic 30 wt% Cu/CeO₂ catalysts, possibly by helping to maintain Cu in a reduced state during reaction.     

Nanostructured quaternary Ni1-xCuxFe2-yCeyO4 complex system: Cerium content and copper substitution dependence of cation distribution and magnetic-electric properties in spinel ferrites

Quaternary Ni_1-xCu_xFe_2-yCe_yO₄ complex nano-ferrites system with different cerium content ratio and copper substitution degree were synthesized via co-precipitation wet chemical technique. The newly obtained nanoparticles, with general formula Ni_1-xCu_xFe_2-yCe_yO₄ (where x = 0.0, 0.3, 0.6 and y = 0.00, 0.03, 0.05, 0.08 and 0.10) were heated up to 600 °C to stabilize the specific crystalline spinel structure. The limit of cerium content was quantitively determined to be around 0.08 and up to 0.10. Furthermore, the powders were pelletized in a 13 mm wide pellets and thermally treated at 950 °C. The thermal treatment affected even more the phases segregation process, as CeO₂ was identified in the sample with lowest degree of cerium insertion – 0.03. Also, a difference in color and size of pelletized samples was noticed after the 950 °C thermal treatment. The Rietveld refinement, crystal structure confirmation, morphology magnetic and electrical properties of samples have been deeply studied. The cation distribution carried out from Rietveld refinement confirms the occupancy of (Fe³⁺) on tetrahedral sites and [Ni²⁺], [Cu²⁺], [Fe³⁺] and [Ce²⁺] on octahedral sites in the crystal lattice. Preliminary information regarding the cation distribution in spinel structures were suggested by FTIR spectral results, precisely in the 650-520 cm^?1 region, as a consequence of peak shape and lack of shiftiness of M^Td – O bond. Spherical-shaped quaternary nano-ferrites of 17–28 nm were determined from FE-SEM analysis and the samples composition was confirmed by EDX analysis. Hysteresis loops shows modifications in coercivity, magnetization and magnetic remanence with Ni²⁺ and Cu²⁺ ions doping in Ni_1-xCu_xFe_2-yCe_yO₄ complex systems with typical ferrimagnetic behavior. Dielectric measurements were employed in order to determine the electrical permittivity, dielectric losses and conductivity values in a 10 Hz – 1 MHz frequency range.