Screening of Mono-, Di- and Trivalent Cationic Dopants for the Enhancement of Thermal Behavior, Kinetics, Structural, Morphological, Surface and Magnetic Properties of CoFe2O4-SiO2 Nanocomposites.

CoFe2O4 is a promising functional material for various applications. The impact of doping with different cations (Ag+, Na+, Ca2+, Cd2+, and La3+) on the structural, thermal, kinetics, morphological, surface, and magnetic properties of CoFe2O4 nanoparticles synthesized via the sol-gel method and calcined at 400, 700 and 1000 °C is investigated. The thermal behavior of reactants during the synthesis process reveals the formation of metallic succinates up to 200 °C and their decomposition into metal oxides that further react and form the ferrites. The rate constant of succinates' decomposition into ferrites calculated using the isotherms at 150, 200, 250, and 300 °C decrease with increasing temperature and depend on the doping cation. By calcination at low temperatures, single-phase ferrites with low crystallinity were observed, while at 1000 °C, the well-crystallized ferrites were accompanied by crystalline phases of the silica matrix (cristobalite and quartz). The atomic force microscopy images reveal spherical ferrite particles covered by an amorphous phase, the particle size, powder surface area, and coating thickness contingent on the doping ion and calcination temperature. The structural parameters estimated via X-ray diffraction (crystallite size, relative crystallinity, lattice parameter, unit cell volume, hopping length, density) and the magnetic parameters (saturation magnetization, remanent magnetization, magnetic moment per formula unit, coercivity, and anisotropy constant) depend on the doping ion and calcination temperature.

Recent Advances in Synthesis, Characterization and Applications of Innovative Materials in Removal of Water Contaminants.

Water is a scarce resource with a close and intricate nexus with energy [...].

Investigation of Structural, Morphological and Magnetic Properties of MFe2O4 (M = Co, Ni, Zn, Cu, Mn) Obtained by Thermal Decomposition.

The structural, morphological and magnetic properties of MFe2O4 (M = Co, Ni, Zn, Cu, Mn) type ferrites produced by thermal decomposition at 700 and 1000 °C were studied. The thermal analysis revealed that the ferrites are formed at up to 350 °C. After heat treatment at 1000 °C, single-phase ferrite nanoparticles were attained, while after heat treatment at 700 °C, the CoFe2O4 was accompanied by Co3O4 and the MnFe2O4 by α-Fe2O3. The particle size of the spherical shape in the nanoscale region was confirmed by transmission electron microscopy. The specific surface area below 0.5 m2/g suggested a non-porous structure with particle agglomeration that limits nitrogen absorption. By heat treatment at 1000 °C, superparamagnetic CoFe2O4 nanoparticles and paramagnetic NiFe2O4, MnFe2O4, CuFe2O4 and ZnFe2O4 nanoparticles were obtained.

Dependence of Structural, Morphological and Magnetic Properties of Manganese Ferrite on Ni-Mn Substitution.

This paper presents the influence of Mn2+ substitution by Ni2+ on the structural, morphological and magnetic properties of Mn1-xNixFe2O4@SiO2 (x = 0, 0.25, 0.50, 0.75, 1.00) nanocomposites (NCs) obtained by a modified sol-gel method. The Fourier transform infrared spectra confirm the formation of a SiO2 matrix and ferrite, while the X-ray diffraction patterns show the presence of poorly crystalline ferrite at low annealing temperatures and highly crystalline mixed cubic spinel ferrite accompanied by secondary phases at high annealing temperatures. The lattice parameters gradually decrease, while the crystallite size, volume, and X-ray density of Mn1-xNixFe2O4@SiO2 NCs increase with increasing Ni content and follow Vegard's law. The saturation magnetization, remanent magnetization, squareness, magnetic moment per formula unit, and anisotropy constant increase, while the coercivity decreases with increasing Ni content. These parameters are larger for the samples with the same chemical formula, annealed at higher temperatures. The NCs with high Ni content show superparamagnetic-like behavior, while the NCs with high Mn content display paramagnetic behavior.

Impact of Ni Content on the Structure and Sonophotocatalytic Activity of Ni-Zn-Co Ferrite Nanoparticles.

The structure, morphology, and sonophotocatalytic activity of Ni-Zn-Co ferrite nanoparticles, embedded in a SiO2 matrix and produced by a modified sol-gel method, followed by thermal treatment, were investigated. The thermal analysis confirmed the formation of metal succinate precursors up to 200 °C, their decomposition to metal oxides and the formation of Ni-Zn-Co ferrites up to 500 °C. The crystalline phases, crystallite size and lattice parameter were determined based on X-ray diffraction patterns. Transmission electron microscopy revealed the shape, size, and distribution pattern of the ferrite nanoparticles. The particle sizes ranged between 34 and 40 nm. All the samples showed optical responses in the visible range. The best sonophotocatalytic activity against the rhodamine B solution under visible irradiation was obtained for Ni0.3Zn0.3Co0.4Fe2O4@SiO2.

Impact of anthropogenic activities on water quality parameters of glacial lakes from Rodnei mountains, Romania.

The aim of this paper is to assess the water quality from several lakes in Rodnei Mountains National Park, in order to establish the extent to which the anthropic activities, such as livestock and tourism affect the water characteristics. The paper presents the quality status of 13 water samples, collected from different mountain lakes from Romania, by monitoring 25 quality indicators, 21 metals and metalloids. The results indicate relatively high content of NH4+ (0.96 mg/L), NO2- (0.240 mg/L), Ca (38.44 mg/L), Mg (4.35 mg/L), Fe (288 mg/L), Cu (34.46 µg/L) and high values for turbidity (5.31 NTU), chemical oxygen demand (10.00 mgO2/L) and suspended materials (88.0 mg/L). Microbiological analyses were performed for 14 types of bacteria. In some samples, the faecal coliforms (1100 bacteria/mL), faecal streptococci (39 bacteria/mL) and aerobic heterotrophic bacteria at 37 °C (300 bacteria/mL) were relatively in a high content. The metal pollution indices (heavy metal pollution index -HPI, heavy metal evaluation index -HEI and the degree of contamination -Cd) indicated as well that the water samples presented no metal pollution. Values ranged from 5.17 to 27.84 for HPI, 0.55 to 5.07 for HEI and -8.45 to -3.93 for Cd were obtained. The water quality index (WQI) indicated excellent and good quality for the studied samples, with a mean of 22.6 and a range from 11.4 to 46.9.

Chemical modeling of groundwater quality in the aquifer of Seini town - Someș Plain, Northwestern Romania.

This paper presented a groundwater quality monitoring in Seini town, North-West of Romania, by assessing 18 physicochemical parameters (pH, EC, COD, turbidity, ht, NH4+, NO2-, NO3-, Cl-, Al, Fe, Mn, Pb, Zn, Cd, Cr, Ni and As) from 12 private dug wells and 5 private drilled wells, each with unique characteristics and used as a drinking water source. The pollution, quality status and risk assessment of drinking water sources were assessed, by pollution, quality and risk indices. Statistical methodology and cluster analysis were applied in order to elaborate and improve upon a mathematical model. 2 D and 3 D mathematical models were elaborated to show the functions that better describe the dependence between a set of physicochemical parameters. Heavy metal pollution index (HPI) and heavy metal evaluation index (HEI) results indicated that the studied drinking water sources presented no heavy metal contamination. Human health risk assessment indices showed that the consumption of studied waters presented no non-carcinogenic risk at heavy metals, but potential non-carcinogenic risk at NO3-. The water quality index (WQI) classifies the majority of samples as waters with excellent quality and the minority of samples in waters with poor and very poor quality. By geostatistical techniques, the spatial patterns of the main physicochemical indicators were established for both the surface of the aquifer and its depth. The aim of the water quality study was to establish the toxicity degree of water, its influence on human health and to inform the population regarding the use of individual water sources.

Assessment of Water Physicochemical Parameters in the Strîmtori-Firiza Reservoir in Northwest Romania.

This article assesses the surface water quality of the Strîmtori-Firiza reservoir by analyzing 14 physicochemical parameters among 9 metals in 18 sampling points. A series of possible reservoir pollutants were identified, depending on the nature of the pollutants and their loading. The novelty of the paper consists in the broad spectrum of investigations that includes spatial distribution cluster analysis and mathematical modeling. This article presents an innovative method of assessing the distributions of the metal loads as maps of metal distribution that are in accordance with the developed mathematical models that aim to present the pollutant distribution and the degree of correlation between the physicochemical indicators. The clusters were generated using Ward's and Nearest Neighbor methods that are less used in the studies concerning the analysis of water quality. Measures for maintaining the quality of the water reservoir are proposed considering the importance of the reservoir as source for drinking/industrial water.

Innovative Nanomaterial Properties and Applications in Chemistry, Physics, Medicine, or Environment.

Developing innovative nanomaterials unlocks new opportunities in physics, chemistry, medicine, and environmental protection [...].

The Antioxidant Effect of Burdock Extract on the Oxidative Stability of Lard and Goose Fat during Heat Treatment.

Concerns regarding product quality and nutrition are raised due to the effects of high temperatures on frying fats. The aim of this research was to examine the effects of temperature and burdock extract addition in relation to quality parameters for dietary lard and goose fat exposed to heating. In order to monitor quality changes, animal fats and 0.01% additivated fats were heated at different temperatures (110, 130, 150, 170, 190, and 210 °C for 30 min). Thiobarbituric acid-reactive substances test (TBARS), peroxide value (PV), iodine value (IV), acid value (AV), saponification value (SV), total polar compounds (TPoC), total phenolic content (TPC), fatty acid (FA) content, and microscopic examination were established in order to quantify the level of oxidative rancidity. Heating temperature and additivation had a significant (p < 0.001) effect on peroxide value. In all fats, values of thiobarbituric acid-reactive substances significantly (p < 0.001) increased with heating temperature, but values decreased when burdock extract was added in a proportion of 0.01%. Positive correlations were found between AV and PV for lard (r = 0.98; p < 0.001) and goose fat (r = 0.96; p < 0.001). The heating temperature had a significant effect on total MUFAs in both lard and goose fat (mostly in non-additivated fat). Statistical analysis of the data showed that the addition of burdock extract at a concentration of 0.01% significantly (p < 0.01) reduced the installation of oxidation process in alimentary fats heated at different temperatures. Animal fats were well protected from oxidation by burdock extract, which demonstrated its efficacy as an antioxidant; it may be used to monitor the fats oxidation and to estimate their shelf-life stability.

Heavy metal contamination assessment and potential human health risk of water quality of lakes situated in the protected area of Tisa, Romania.

Protected areas are significant due to the high value of natural resources they shelter. This study's primary objective is to assess the quality status of the water resources (13 lakes and Tisa River) localized in the protected area of Tisa River on the territory of Romania. A number of 13 lakes and surface water (Tisa River) situated in the protected area through the Natura 2000 ecological network are studied. The chemistry and potential pollution status were analyzed by measuring and analyzing a set of twenty elements and sixteen physico-chemical parameters. The potential impact of anthropogenic activities was settled through the applied analysis and obtained results. A potential human health risk was noticed. Results indicated that waters are rich in Ni and Fe probably due to interaction with groundwater rich in Fe and Ni. Waters are characterized by potential contamination, which if directly or through the food chain consumed could negatively influence the human health. Piper and Gibbs plots indicated that the studied waters are divided into three categories based on water-rock interactions: mixed Ca2+-Na+-HCO3-, CaCO3-, and Na+-HCO3-. Likewise, the applied pollution indices (Heavy metal Pollution Index, HPI and Heavy metal Evaluation Index, HEI) indicated three pollution categories correlated to the As, Ni and Fe amounts. The findings of this research imply that the chemistry of the studied lakes and surface waters is influenced by the geogenic origin and emergence of anthropogenic activities. The significance of this research is related to understanding of mechanisms that influence the water quality, improving and conserving the natural water resources, and correspondingly understanding if any potential human health risks could be identified.

Chemical Assessment of Drinking Water Quality and Associated Human Health Risk of Heavy Metals in Gutai Mountains, Romania.

Chemical data compiled from field and laboratory studies were analysed on drinking water sources from a mountain area (Gutai Mountains) in Romania. Six physico-chemical indicators, nine anions, and twenty-one metals were determined and analysed. The results of this study showed that waters are generally rich in NH4+ and NO2-, exceeding the recommended limit of 0.5 mg NH4+/L, while some waters are rich in As, Cd, Mn and Pb, but with concentrations below the limits concerning the use of waters with drinking purposes. The applied heavy metal pollution indices (scores: 0.56-47.9) indicate that more than 50% of samples are characterized by medium pollution degrees. Based on the results obtained, it was determined that geological and human activities were influential in enriching the studied waters with the chemicals considered. Emphasizing this aspect related to pollution sources and the importance of a clean chemical status that must characterize waters used for drinking purposes, a human health risk assessment for heavy metals was implemented. The results indicated that even though the studied waters are rich in heavy metals, scores related to the risk assessment of heavy metals indicated a lack of non-carcinogenic risks for As, Mn, Cd and Cu. Nevertheless, this study and the results obtained are significant at national and international levels by offering a perspective on determining the potential pollution and associated human health risks at heavy metals in drinking water sources from a mountain area.

Assessing microbiological and heavy metal pollution in surface waters associated with potential human health risk assessment at fish ingestion exposure.

Fish represent a significant source of nutrients but also cause negative health effects due to their bioaccumulation capacity for pollutants. The aim of this study was to examine the transfer of metals from the water of several rivers (Somes, Tisa, Sasar, Lapus, Lapusel) to fish (Caras sp) tissue (subcutaneous fat, muscles, liver, intestines, kidneys, gills, brain, and eyes) and to identify and assess the carcinogenic and non-carcinogenic health risks of Arsenic (As), Cadmium (Cd), Nickel (Ni), Manganese (Mn), Cooper (Cu), Lead (Pb), Chromium (Cr) and Zinc (Zn) through the ingestion of fish (muscles and subcutaneous fat tissues). The obtained results indicated that a diet consisting of fish is particularly vulnerable, particularly in children compared to adults. The risk assessment results were below the threshold limit, although the fish samples contained heavy metals, with values exceeding the permitted limits of Fe (4.41-1604 mg/kg), Cr (727-4155 µg/kg), Zn (4.72-147 mg/kg), and Ni (333-2194 µg/kg). The studied surface waters are characterized by low and high degrees of pollution with heavy metals, as indicated by the heavy metal pollution index scores (HPI: 12.4-86.4) and the heavy metal evaluation index scores (HEI: 1.06-17.6). The considerable pollution levels are attributed to the high Mn content (0.61-49.7 µg/kg), which exceeded the limit up to fifty times. A consistent set of physico-chemical analysis (pH, electrical conductivity, total hardness, turbidity, chloride, sulphate, nitrate, nitrite, ammonium, Ca, Mg, Na, K) was analysed in water samples as well. Considering the water quality index scores (WQI: 16.0-25.2), the surface waters exhibited good quality. Microbiological results indicated the presence of Listeria monocytogenes and atypical colonies of coagulase-positive staphylococcus in fish. In contrast, the surface waters from which fish samples were collected were positive for Escherichia coli, and coliform bacteria intestinal Enterococci. Based on the study's results, it is recommended to exercise caution in the case of children related to the consumption of fish and using the waters for drinking purposes. This study provides important data of considerable novelty to the riparian population, researchers, and even policy makers on the quality status and potential levels of contamination of river waters, fish and the bioaccumulation of heavy metals in fish that may cause adverse effects on human health if consumed, and similarly the heavy metal pollution degree of waters and the non-carcinogenic risk of heavy metals through ingestion and skin absorption of water in children and adults (the study area is a significant source of fisheries).

Synthesis, Physicochemical Characterization and Applications of Advanced Nanomaterials.

This Special Issue highlights the last decade's progress regarding new nanostructured materials. In this regard, the development of nanoscale syntheses and innovative characterization tools that resulted in the tailored design of nanostructured materials with versatile abilities in many applications were investigated. Various types of engineered nanostructures, usually metal nanoparticles or nanoporous metal oxides, have been synthesized for various applications. This Special Issue covers the state-of-the-art of advanced nanoparticles in many disciplines (chemistry, pharmacy, nanomedicine, agriculture, catalysis, and environmental science). The crystallite sizes depended on the annealing temperature and type of doping ion. A combination of rigid and soft particles could simultaneously enhance both the tensile properties and the fracture toughness, which could not be achieved by the single-phase particles independently. The surface charge and in vitro corrosion resistance are key parameters characterizing biomaterials in the interaction of the implant with the biological environment. Solar energy in the presence of a photocatalyst can be effectively converted into electricity/fuel, break down chemical and microbial pollutants, and help water purification. The saturation magnetization, remanent magnetizations, coercivity, and anisotropy were found to depend on the doping ion, annealing temperature, and particle size. The efficiency of the photocatalysis reaction depends on several factors, including light absorption capacity/light intensity, the type of photocatalyst used, the concentration of a photocatalyst and contaminant particles, the pH of the reaction medium, etc. The variety of color pigments and coloring properties of the targeted application in the ceramic industry was also of interest.

Water quality assessment of Remeți watercourse, Maramureș, Romania, located in a NATURA 2000 protected area subjected to anthropic pressure.

The study assessed the evolution of water indicators of Remeți water body that is located in the Remeți locality in the Upper Tisa, a Natura 2000 protected area. Thus, electric conductivity, dissolved oxygen, oxygen saturation, temperature, pH, turbidity, ammonium concentration (NH4+), nitrates (NO3-), nitrites (NO2-), orthophosphate (PO43-), dissolved Fe, Mn, water hardness, alkalinity (A) and chloride were measured over the January (I)-October (X) 2021 period. This water course was subjected to anthropic pressure, being polluted with nutrients such as ammonium and orthophosphate ions, iron and manganese. The concentrations of other metals were either low (Al, Ba, Li, Ga, Rb, Ni, Sr, Zn, Cu, Ti) or below the detection limit (Pb, Cd). The study was performed over a period of 8 months, namely January 2021-October 2021, covering the 4 seasons, in order to establish their influence on the level of water quality indicators. Exceeded turbidity values and high concentrations of ammonium, orthophosphate and dissolved iron were found, these being generally higher in the summer-autumn months. Dissolved oxygen concentrations were low in the summer-autumn months. Based on the values of the physico-chemical indicators, two types of water quality indices WA-WQI (weighted arithmetic water quality indices) and CCME-WQI (Canadian Council of Ministers of the Environment water quality indices) were calculated to evaluate the global water quality and its evolution over the seasons with a single value. WA-WQI values varied in the range of 78.56-761.63, with a tendency to increase in autumn, showing an intensified tendency of global water quality deterioration due to an increase in ammonium, turbidity, iron and orthophosphates in autumn months while CCME-WQI values were between 39.6 and 68.9, being fair in winter-spring months and marginal / bad in summer and autumn months. The results of this study are advantageous in identifying the level of pollution of Remeți water course, being a signal for local authorities in taking the necessary measures to reduce the pollution around it, for a better human health and conservation of the ecosystems hosted in the protected area.

Preparation and Characterization of the Composition of Volatile Compounds, Fatty Acids and Thermal Behavior of Paprika.

This study aimed to investigate the thermal behavior and composition of volatile compounds, fatty acids and polyphenols in paprika obtained from peppers of different countries. The thermal analysis revealed various transformations in the paprika composition, namely drying, water loss and decomposition of volatile compounds, fatty acids, amino acids, cellulose, hemicellulose and lignin. The main fatty acids found in all paprika oils were linoleic (20.3-64.8%), palmitic (10.6-16.0%) and oleic acid (10.4-18.1%). A notable amount of omega-3 was found in spicy paprika powder varieties. The volatile compounds were classified into six odor classes (citrus (29%), woody (28%), green (18%), fruity (11%), gasoline (10%) and floral (4%)). The total polyphenol content ranged between 5.11 and 10.9 g GA/kg.

Effects of Lanthanum Substitution and Annealing on Structural, Morphologic, and Photocatalytic Properties of Nickel Ferrite.

Nanoparticles of NiLaxFe2-xO4 ferrite spinel incorporated in a SiO2 matrix were synthesized via a sol-gel method, followed by annealing at 200, 500, and 800 °C. The resulting materials were characterized via XRD, AFM, and BET techniques and evaluated for photocatalytic activity. The XRD diffractograms validate the formation of a single-phase cubic spinel structure at all temperatures, without any evidence of secondary peaks. The size of crystallites exhibited a decrease from 37 to 26 nm with the substitution of Fe3+ with La3+ ions. The lattice parameters and crystallite sizes were found to increase with the rise in La3+ content and annealing temperature. Isotherms were employed to calculate the rate constants for the decomposition of malonate precursors to ferrites and the activation energy for each ferrite. All nanocomposites have pores within the mesoporous range, with a narrow dispersion of pore sizes. The impact of La content on sonophotocatalytic activity was evaluated by studying Rhodamine B degradation under visible light irradiation. The results indicate that the introduction of La enhances nanocomposite performance. The prepared Ni-La ferrites may have potential application for water decontamination.

Chemical Analysis of Various Tea Samples Concerning Volatile Compounds, Fatty Acids, Minerals and Assessment of Their Thermal Behavior.

Tea is the most consumed drink worldwide due to its pleasant taste and various beneficial effects on human health. This paper assesses the physicochemical analysis of different varieties of tea (leaves, flowers, and instant) after prior drying and fine grinding. The thermal decomposition behavior of the tea components shows that the tea has three stages of decomposition, depending on temperature. The first stage was attributed to the volatilization of water, while the second stage involved the degradation of volatiles, polyphenols, and fatty acids. The degradation of cellulose, hemicellulose, and lignin content occurs at the highest temperature of 400 °C in the third stage. A total of 66 volatile compounds, divided into eight classes, were identified in the tea samples. The volatile compounds were classified into nine odor classes: floral, fruity, green, sweet, chemical, woody, citrus, roasted, and alcohol. In all flower and leaf tea samples, monounsaturated (MUFAs), polyunsaturated (PUFAs), and saturated fatty acids (SFAs) were identified. A high content of omega-6 was quantified in acacia, Saint John's Wort, rose, and yarrow, while omega-3 was found in mint, Saint John's Wort, green, blueberry, and lavender samples. The flower and leaf tea samples studied could be a good dietary source of polyphenolic compounds, essential elements. In instant tea samples, a low quantity of polyphenols and major elements were identified. The physicochemical analysis demonstrated that both flower and leaf teas have high-quality properties when compared to instant tea.

A Strategy for Tuning the Structure, Morphology, and Magnetic Properties of MnFe2O4/SiO2 Ceramic Nanocomposites via Mono-, Di-, and Trivalent Metal Ion Doping and Annealing.

This work presents the effect of monovalent (Ag+, Na+), divalent (Ca2+, Cd2+), and trivalent (La3+) metal ion doping and annealing temperature (500, 800, and 1200 °C) on the structure, morphology, and magnetic properties of MnFe2O4/SiO2 ceramic nanocomposites synthesized via sol-gel method. Fourier-transform infrared spectroscopy confirms the embedding of undoped and doped MnFe2O4 nanoparticles in the SiO2 matrix at all annealing temperatures. In all cases, the X-ray diffraction (XRD) confirms the formation of MnFe2O4. In the case of undoped, di-, and trivalent metal-ion-doped gels annealed at 1200 °C, three crystalline phases (cristobalite, quartz, and tridymite) belonging to the SiO2 matrix are observed. Doping with mono- and trivalent ions enhances the nanocomposite's structure by forming single-phase MnFe2O4 at low annealing temperatures (500 and 800 °C), while doping with divalent ions and high annealing temperature (1200 °C) results in additional crystalline phases. Atomic force microscopy (AFM) reveals spherical ferrite particles coated by an amorphous layer. The AFM images showed spherical particles formed due to the thermal treatment. The structural parameters calculated by XRD (crystallite size, crystallinity, lattice constant, unit cell volume, hopping length, density, and porosity) and AFM (particle size, powder surface area, and thickness of coating layer), as well as the magnetic parameters (saturation magnetization, remanent magnetization, coercivity, and anisotropy constant), are contingent on the doping ion and annealing temperature. By doping, the saturation magnetization and magnetocrystalline anisotropy decrease for gels annealed at 800 °C, but increase for gels annealed at 1200 °C, while the remanent magnetization and coercivity decrease by doping at both annealing temperatures (800 and 1200 °C).

Influence of SiO2 Embedding on the Structure, Morphology, Thermal, and Magnetic Properties of Co0.4Zn0.4Ni0.2Fe2O4 Particles.

(Co0.4Zn0.4Ni0.2Fe2O4)α(SiO2)(100-α) samples obtained by embedding Co0.4Zn0.4Ni0.2Fe2O4 nanoparticles in SiO2 in various proportions were synthesized by sol-gel process and characterized using thermal analysis, Fourier-transform infrared spectroscopy, X-ray diffraction, transmission electron microscopy, inductively coupled plasma optical emission spectrometry, and magnetic measurements. Poorly crystalline Co-Zn-Ni ferrite at low annealing temperatures (500 °C) and highly crystalline Co-Zn-Ni ferrite together with traces of crystalline Fe2SiO4 (800 °C) and SiO2 (tridymite and cristobalite) (1200 °C) were obtained. At 1200 °C, large spherical particles with size increasing with the ferrite content (36-120 nm) were obtained. Specific surface area increased with the SiO2 content and decreased with the annealing temperature above 500 °C. Magnetic properties were enhanced with the increase in ferrite content and annealing temperature.