Energy Dispersive Microanalysis Research Articles

Chemical Composition and Properties of Water-Methanol Solution of Formaldehyde

By reacting paraform with methanol and water at concentrations of 10.8, 11.6 and 22.7 mol/l in the presence of catalytic quantities of monoethanolamine, a method was developed for obtaining a bactericide that, at a concentration of 500 mg/l, completely inhibits the formation of hydrogen sulfide in an accumulative culture of planktonic form of sulfate-reducing bacteria with a quantity of 106 cells/ml. The composition of the resulting bactericide, its effectiveness and corrosion properties were studied. Using scanning electron microscopy using a system for energy-dispersive microanalysis, it was shown that the corrosion products formed during the corrosive action of the bactericide on St-20 steel are iron oxides.

Experimental study on the micro-mechanical parameters of Ni-based single-crystal superalloys using nanoindentation and element distribution analysis

Ni-based single-crystal superalloys are normally prepared by directional solidification. Due to different solidification sequences, Ni-based single-crystal superalloys exhibit a typical dendritic arm structure, and the element segregation in the dendritic arm can affect the high temperature mechanical properties of the alloy. Solid solution treatment has a certain extent to reduce the inter-dendritic and dendritic arm between the concentrations of the elements, thereby changing the alloy micro-nano view parameters to improve the high temperature mechanical properties of the alloy. In this study, nanoindentation experiments were carried out on the inter-dendritic and dendritic arm of the cast and solid solution samples. The micromechanical parameters were calculated. The amounts of changes in elemental concentration were discussed with the results of the energy dispersive spectroscopy and electron probe microanalysis, so as to analyse the relationship between the micromechanical parameters and the changes in elemental concentration. The results show that solid solution treatment has a significant impact on the elastic modulus, with an increase of 114.7% of the inter-dendritic region and an increase of 142.7% of the dendritic arm. However, solid solution treatment has little effect on the hardness, with no significant change in the hardness of the inter-dendritic region and an increase of 43.86% of the dendritic arm. Solid solution treatment has a more significant effect on improving the segregation behavior of Al and Co elements, with the segregation coefficients of Al and Co elements in the inter-dendritic region decreasing and increasing by 36% and 19%, and the segregation coefficients of Al and Co elements in the dendritic arm region decreasing and increasing by 29% and 34%.

APPLICATION OF ACTIVATING INFLUENCES IN OBTAINING TiO2-PILLARED MONTMORILLONITE WITH IMPROVED PHOTOCATALYTIC PROPERTIES

A new approach to the obtaining of a highly efficient photocatalyst - TiO2-pillared montmorillonite – by hydrothermally activated intercalation of mechanically dispersed bentonite matrix with the polyhydroxocomplexes of titanium is proposed. The material was characterized by the X-ray diffractometry, low-temperature nitrogen adsorption-desorption, scanning electron microscopy, energy dispersive microanalysis, and zeta potential measurement. The use of short-term (up to 3 min) mechanical dispersion in a planetary mill significantly increases the capacity of cation exchange during intercalation, and the photocatalysts obtained after annealing at 500 °C are characterized by significantly higher values of specific surface area and total pore volume compared with mechanically untreated and initial montmorillonite. The average size of TiO2 crystallites is about 10 nm and the content of anatase is over 90%. Mechanical activation leads to a significant change in the ζ-potential of montmorillonite particles from a significantly negative value in the source material to almost zero, which is an additional argument for more efficient intercalation. Hydrothermal treatment leads to the appearance of coral-like formations of titania on the surface of montmorillonite, and after mechanical treatment they significantly increase in size. Adsorption and photocatalytic properties were studied in a quartz reactor using the rhodamine B dye as example. Complete photocatalytic destruction of the dye was achieved within about 100 min (initial concentration of 40 mg/l, amount of photocatalyst 1 g/l, UV lamp power 250 W). Adsorption kinetics is described by pseudo-first and pseudo-second order models. The kinetics of photocatalysis is described by the Langmuir-Hinshelwood model. The high photoactivity is explained both by the improvement of textural properties and the appearance of additional photocatalytic centers due to the defective structure of mechanically activated montmorillonite.

Effect of structure of unfluxed burnt titanomagnetite pellets on strength under static compression

Burnt pellets must retain their strength from the moment they are taken out of an induration machine until they are loaded into a blast furnace. One of the indicators of the burnt pellets’ strength is the compressive strength, i.e. the ultimate force. In experiments to determine compressive strength, the main type of fracture is occurrence and development of cracks that pass through the core center of pellets (where the maximum radial tensile stresses present) or near it. The paper presents the requirements for static compression strength imposed by blast furnace production to iron ore pellets. Using an optical and scanning electron microscope equipped with an energy-dispersive microanalyzer, we analyzed the relationship of structural components and pores in the core of burnt unfluxed iron ore titanomagnetite pellets with the ultimate force under static compression. By scanning electron microscopy and X-ray spectral microanalysis, it was established that the core of pellets is a multiphase material, and its main phases are titanomagnetite, magnetite, titanohematite, hematite and aluminosilicate binder. Optical microscopy made it possible to establish the microstructure of the pellet core, which has three types of microstructures: non-oxidized core (magnetite or titanomagnetite), partially oxidized core – around (magnetite or titanomagnetite) hematite grains (titanohematite) and oxidized core (hematite and titanohematite). The main factors for obtaining pellets with an ultimate force of more than 2.5 kN/pellet according to the requirements of blast furnace production are: the number of closed macropores and the number of large grains in the core. It is shown that with an increase in the number of closed macropores and the number of large grains in the core, the ultimate force is reduced from 3.5 kN to 0.87kN/pellet.

Antibacterial Calcium Phosphate Coatings with Zinc Oxide Nanoparticles

Porous calcium phosphate coatings (C-P) with ZnO nanoparticles were obtained via the micro-arc oxidation method on a titanium substrate. ZnO nanoparticles were added to the C-P coatings to change the zeta potential and improve the coatings’ bioactivity and antibacterial properties. The samples with coatings were studied via scanning electron microscopy (SEM), X-ray diffraction, energy dispersive microanalysis, potentiodynamic polarization, and zeta potential measurement. The coatings modified with ZnO nanoparticles showed improved physical, electrochemical, and electrical properties, compared to the initial unmodified coatings. Modification with ZnO nanoparticles contributed to an increase in zeta potential from −60 mV to −53 mV. Functionalization of the coatings with ZnO nanoparticles allowed us to increase the anticorrosion characteristics by about 30%. The biological studies showed that the coatings had no cytotoxic effect on L929 fibroblast cells. The antibacterial activity of the coating rose by 99% after the addition of ZnO nanoparticles against the bacterium Staphylococcus aureus.

GEOCHEMICAL CONDITIONS OF SULLAR SPRING: FORMATION OF AUTHIGENIC MINERALS AND METHANE FLUXES

Link for citation: Soldatova E.A., Sidkina E.S., Kiriukhin B.A., Maximov P.N., Krivenok L.A., Ivanov V., Tananaev N.I. Geochemical conditions of Sullar spring: formation of authigenic minerals and methane fluxes. Bulletin of the Tomsk Polytechnic University. Geo Аssets Engineering, 2023, vol. 334, no. 10, рр. 16-33. In Rus. Relevance and the research object. Interpermafrost aquifers and areas of their discharge with seasonal ice covers are special permafrost-hydrogeological and hydrochemical systems that are not typical for the thick continuous permafrost zone of Central Yakutia. Differences in chlorofluorocarbon content indicate the anaerobic conditions of some springs suggesting microbial degradation of these compounds by methanogenic bacteria. In the discharge area of such springs, a sharp change in the geochemical conditions takes place leading to a transformation in the water chemical composition and boosting the processes of authigenic mineral formation in this buffer area. In current work we considered the geochemical system of the Sullar spring – the most northern and the least studied among interpermafrost groundwater discharge zones of the Lena River right bank. Intensive accumulation of authigenic minerals was found in the Sullar discharge area during field research. It was Fe compounds with bacterial mats as an opalescent film. Some researchers state the connection between the transformation of Fe compounds during permafrost melting and the migration and transformation of organic matter, including its consumption by microorganisms with further methane emission. We assumed that there is a relationship between the authigenic mineral formation and the content and emission of methane in the discharge area of the spring. This research is the first comprehensive description of the hydrochemistry of the interpermafrost water of the Sullar spring. The aim of the research was to explore influence of geochemical conditions and microbial communities on formation of authigenic minerals and methane fluxes, in particular the effect of the change of geochemical conditions due to groundwater discharge on Fe precipitation and to analyze the relation of that process with methane fluxes. For this purpose, we study water chemical composition of the Sullar spring, measure methane fluxes from water surface and analyze mineral and microbial composition of secondary mineral crusts and bottom eluvium collected near water sampling points. Methods. The main element content was determined by ion chromatography. The concentrations of the bicarbonate ion and dissolved carbon dioxide were calculated by the equilibrium modeling method based on the pH and Eh values of the system. The content of trace elements was measured by mass spectrometry with inductively coupled plasma. To identify seasonal and annual variability, a retrospective analysis of the water chemical composition of the Sullar spring for the period from 1962 to 2020 was carried out. Methane fluxes were measured using the chamber method. The methane concentration was determined by gas chromatography with a flame ionization detector. The features of the secondary mineral crusts and bottom eluvium were determined using a petrographic microscope. The chemical composition of individual mineral phases was evaluated using a scanning electron microscope equipped with a detector for energy dispersive X-ray spectral microanalysis. The DNA concentration was measured on a fluorimeter. Amplicon libraries were generated by polymer chain reaction with universal primers for the V4 region. Equilibrium modeling was carried out using the HCh software.

Hybrid Polymer–Inorganic Coatings Enriched with Carbon Nanotubes on Ti-6Al-4V Alloy for Biomedical Applications

Bone tissue degeneration, caused by disease as well as trauma, is a problem affecting many social groups in the 21st century. It involves pain and reduced patient comfort. Developments in materials engineering allow for the design of novel, innovative materials that can be used in therapies to promote bone regeneration. This work presents the preparation of a ceramic–polymer coating modified with carbon nanotubes on a titanium alloy for biomedical applications. The ceramic part is hydroxyapatite synthesized by the wet precipitation method using orthophosphate and calcium hydroxide. The polymer of choice was polyethylene glycol. A UV light synthesis method was successfully applied to obtain coatings characterized by continuity and full crosslinking. Extensive physicochemical analysis and incubation studies were carried out. Interactions between coatings and fluids mimicking artificial biological environments were analyzed for 9 days, i.e., in fluids such as SBF solution, artificial saliva, and distilled water. During the in vitro incubation, changes in pH values were measured by potentiometric tests, and ionic conductivity was measured by analyzing conductometry. After incubation, the surface morphology was studied by scanning electron microscopy (SEM) together with energy-dispersive (EDS) microanalysis, which made it possible to determine the presence of individual elements on the surface, as well as to observe the appearance of new apatite layers. Fourier-transform infrared (FT-IR) spectrometry was also performed before and at the end of the incubation period. On the basis of the presented studies, it was concluded that coatings that contain nanotubes are bioactive and do not negatively affect the properties of the coatings. Bioactivity was confirmed microscopically by observing new apatite layers after incubation in SBF, which were identified as phosphorus and calcium deposits. Degradation of the polymer phase was observed in the artificial saliva. These materials require further study, including safety analysis, but they demonstrate potential for further work.

Ensembles of spectral-spatial convolutional neural network models for classifying soil types in hyperspectral images

The paper presents a study of various approaches to the classification of soil covers based on neural network algorithms using hyperspectral remote and proximal sensing of the Earth. The spectral distributions were recorded in the laboratory using an Offner imaging scanning hyperspectrometer. Spectral-spatial characteristics of nine soil samples from various parts of a farming land in the Samara region were experimentally studied. Using a method of energy dispersion microanalysis, the correspondence between the hyperspectral data and the chemical composition of the samples taken was established. Based on the data obtained, a neural network-aided classification of soil samples was implemented depending on the content of constituent elements such as carbon and calcium. A normalized spectral-spatial convolutional neural network was used as a classifier. As a result of the work, an approach to the classification of high-resolution hyper-spectral images based on the refinement of a multiclass convolutional neural network using an ensemble of binary classifiers is proposed. It is shown that the classification of soil samples by carbon and calcium content is carried out with an accuracy of 0.96.

Characterization and provenance of Roman tiles from the archaeological sites of Cariati, Scala Coeli and Terravecchia (Calabria, Southern Italy)

This paper concerns the archaeometric study carried out on a group of tiles and a brick belonging to the Roman period. In particular, the samples are dated back to the late 3rd-1st century BC and they come from the archaeological sites of Cariati, Scala Coeli and Terravecchia, in the province of Cosenza (Calabria, Southern Italy). Some of these samples are impressed with the stamps L./N. LUSIPETEL and M. MECONI, belonging to a production plant that operated in the north-central Ionian coast of the Calabria Region between the late Republican period and the Imperial age, owned to two important families of Petelia (today Strongoli). All samples were analyzed by Optical microscopy, X-ray Powder Diffraction and Energy Dispersion Microanalysis by Scanning Electron Microscope, in order to determine their minero-petrographic features and their geochemical composition, to identify the extraction area of the raw materials and the technological aspects related to the processing of the clay. In addition, the comparison between the chemical composition of the samples with the clay and the sand coming from some quarries of the Cariati area confirms that most of the samples were locally produced using raw materials from natural Pliocene outcrops.

Dissimilar autogenous TIG joint of Alloy 617 and AISI 304H steel for AUSC application

To reduce costs and improve high-temperature performance in Advanced Ultra Super Critical (AUSC) boilers, it is necessary to weld austenitic steel to Inconel alloy. In this study, the autogenous tungsten inert gas (TIG) welding process was used to join Alloy 617 and an austenitic AISI 304H steel plate of thickness 5 mm. Microstructural analysis showed that the microstructure formation was uneven along the weldments, with columnar and cellular dendrites near the interface while the central area of the weld exhibited a combination of columnar, cellular, and equiaxed dendrites. The use of energy dispersive spectroscopy and electron probe micro-analysis unveiled the presence of an unmixed layer at the interface between the weld and AISI 304H steel. Furthermore, a notable variation in the concentration of alloying elements such as Fe, Cr, Ni, Co, and Mo was observed. Within the weld metal, inter-dendritic areas showed the presence of precipitates rich in Cr, Ti, and Mo. Meanwhile, the heat-affected zone (HAZ) of Alloy 617 exhibited the presence of phases like Cr and Mo-rich M23C6 as well as Mo-rich M6C. Hardness tests showed non-uniform hardness along the weldments, with a hardness of 199 ± 6 HV in the weld metal and 225 ± 4 HV in Alloy 617 HAZ, and 207 ± 7 HV in AISI 304H HAZ. The Mo and Cr segregation in the inter-dendritic spaces led to a decline in the tensile properties of the welded parts and resulted in failure from the region of the weld metal.

Cerium and aluminum molybdates as inhibitors of the aluminum AA1050 corrosion process in aqueous NaCl solutions

AbstractCerium molybdate and aluminum molybdate were synthesized by precipitation at controlled pH. The inhibitory properties of these solids on the corrosion process of aluminum in near‐neutral aqueous NaCl solutions were studied. Potentiodynamic polarization curves showed that both molybdates act as mixed‐type inhibitors. This is due to molybdate anion acts as an anodic inhibitor, while the trivalent cations Ce(III) and Al(III) have an inhibitory effect on the cathodic reaction. Linear polarization tests demonstrated a large increase in polarization resistance when these solids are added, resulting in an inhibition efficiency of 97% in both cases. Scanning electron microscopy and X‐ray energy dispersive microanalysis of the exposed surfaces revealed the formation of compact protective films rich in Mo and with no detectable Cl levels.

Ca oxalates in lichen genus Cladonia on the dumps of the Sugur copper deposit (South Urals)

Ca oxalate crystals (mainly, weddellite (Ca(C2O4) • (2.5-x)H2O) are found in the lichen Cladonia chlorophaea on dumps of the Sugur copper deposit underwent to aerosol emissions from the Karabash copper smelting (KCS), South Urals. The samples of lichens and substrate are studied by scanning electron microscopy, energy-dispersion microanalysis, X-ray phase analysis and inductively coupled plasma mass spectrometry. The contents of toxic elements (Cu, Zn, Pb, Cd, Sn, Sb, Se, As, Te) of substrate and lichen thalli exceed their average contents in the Earth’s crust, whereas their contents in thalli are lower than in substrate (except for Cd). The high Pb content is associated with Ca oxalate. The lichen thalli contains inclusions of minerals, which compose the dump, and spherical particles, which are associated with the activity of the KCS and which contain signifcant concentrations of heavy metals. Keywords: calcium oxalates, weddellite, biomineralization, Cladonia, Karabash copper smelter, Sugur copper deposit,

Corrosive Activity of Microorganisms Isolated from Fouling of Structural Materials in the Coastal Zone of the Barents Sea

Potentially corrosive active microorganisms isolated from structural materials with signs of biofouling on the coast of Kislaya Bay (Barents Sea, Russia) were studied: sulfate-reducing, iron-oxidizing and sulfur-oxidizing bacteria. Cultures of sulfate-reducing bacteria (Desulfovibrio sp., Halodesulfovibrio sp.), sulfur-oxidizing bacteria (Dietzia sp.), and iron-oxidizing bacteria (Pseudomonas fluorescens, Bacillus sp.) were identified on the basic of the determining the nucleotide sequences of the 16S rRNA gene. The methods of scanning electron microscopy, energy dispersive microanalysis of the chemical composition and X-ray phase analysis revealed significant changes in the structure and chemical composition of the surface layer of steel reinforcement samples exposed for 28 days in the presence of isolated microorganisms that demonstrated their active participation in corrosion processes. It has been shown that the formation of mineral analogues in corrosion products depends on the strains of studied bacteria and peculiarities of their metabolism. Sulfate-reducing bacteria isolated from the littoral zone of the Barents Sea showed the highest activity in the development of corrosion processes.

MICROSTRUCTURE OF A CrSi2 TRANSITION LAYER PRODUCED BY HOT PRESSING OF Cr AND Si

Hot pressing of a Si single crystal in the bulk of electrolytic Cr powder at 1213 K, with subsequent annealing in air, leads to the formation of an intermediate polycrystalline silicide layer at the interface between the initial components. The phase composition and microstructure of the transition layer and its vicinity were investigated by scanning electron microscopy, X-ray energy-dispersive microanalysis, and electron backscatter diffraction. The transition layer has a crystal structure of the hexagonal phase of chromium disilicide (sp. gr. P6222). An additional annealing up to 120 h leads to insignificant recrystallization of small grains into larger ones.

Composition and formation conditions of nephrite, Nyrdvomenshor deposit, Polar Urals

Research subject. Nephrite and related rocks from the Nyrdvomenshor deposit in the Polar Urals were studied. The Nyrdvomenshor deposit is located in the exocontact of the Rai-Iz ultramafic massif, confined to the Main Ural Fault. The deposit was developed in the process of geological exploration; a license has been issued for a part of the deposit. Aim. To study the nephrite and related rocks from alluvial of the deposit, to formulate a model of its origin. Methods. Qualitative characteristics were assessed visually using a binocular microscope and a special flashlight. The chemical composition was determined by the X-ray fluorescence method. The contents of trace elements were determined by ICP-MS analysis. The mineral composition was studied on a scanning electron microscope with an energy dispersive microanalysis system. Measurements of the isotopic composition of oxygen were carried out. Results. In addition to vesuvianite rodingite, hydrogarnet rodingite was found to be common at the deposit. The studied nephrite is substandard. Tremolite predominates in nephrite, diopside forms relic grains. Uvarovite is widespread, forming both idiomorphic grains, sometimes sheath, less often elongated xenomorphic, and replacing chromite. Omphacite overgrows grains of chromite and uvarovite. Grains of the Fe-dominant mineral of the shuiskite group are noted. Conclusions. Nephrite was formed through both metamorphic and metasomatic processes. Serpentinite was replaced by diopside, which was then replaced by nephrite. Metamorphism enhanced the metasomatism of the serpentinite melange and provided the cryptocrystalline tangled fibrous structure of the nephrite. Then metamorphism and metasomatism led to the formation of omphacite and cracking of the nephrite, which reduced its quality. As these processes progressed, the contribution of the crustal fluid increased, which is confirmed by the results of studying the oxygen isotopic composition of nephrite and other rocks of the deposit.

Оценка несущей способности контактного соединения полюсного вывода свинцовой аккумуляторной батареи

Introduction. The data given in the article show that the problem of increase of fire safety at operation of vehicles is actual. The main purpose of the article is to develop a scientifically based method of examination of contact connections of pole terminals of starter batteries, which have signs of high transient resistance or change in geometrical shape in order to find out the reason of damage in the course of fire-technical expertise. Materials and methods. The researches were carried out with the use of a scanning-electron microscope JSM-6390LV with an attachment for energy-dispersive microanalysis. The objects of research were pole terminals of a lead-acid storage battery of European type and their tips. Contact surfaces of the tips were analyzed without preliminary sample preparation. Theoretical background (theory and calculations). A physical and mathematical model of ultimate load-bearing capacity of lead battery terminal, which corresponds to real design, has been developed. On this basis, there is formulated a computational and practical algorithm for expert analysis of its mechanical and geometrical characteristics. The solution has been simplified to short calculating formulas, allowing to estimate the contact load-bearing capacity. The applicability of the developed mathematical model to carrying out fire-technical exami­nations is shown by a concrete example. Results and discussion. Examples are given of car fires, which were caused by loss of load-bearing capacity in the contact of battery terminals with wire-end terminals during in the process of operation. Pictures of the result of high transient resistance on the contact surface and its elemental composition are given. Experimental data confirmed that the transfer of the material of the pole leads to the tips of wires in the form of drops of lead and its layers is a significant forensic feature in determining the cause of the fire. Conclusions. The method of determination of load-bearing capacity of contact of a lead battery pole to the wire end, on the basis of which it is possible to draw a conclusion about participation of great transient resistance in the contact to the subsequent fire, is offered. The data given in the article may be used by specialists during an expert examination of lead battery terminals, seized from places of fires, in order to establish the mechanism of their damage and, finally, the cause of a fire.

Research of the thermal effect on the Fe–Cr–Al alloy foil in the initial state and with the deposited secondary support

Abstract The purpose of this work is to study the influence of thermal effect on the surface morphology of the Fe–Cr–Al (Kh15Yu5) alloy foil and the elemental composition of the surface layers. Also, studies have been carried out on the physicochemical characteristics of the primary support with the deposited secondary support in the initial state and within the temperature range from 25 to 900 °C. The research was carried out on a JSM 6610 LV, JEOL scanning electron microscope with an installed INCA Energy 450 energy-dispersive microanalysis system. Before depositing secondary support (aluminum oxide), for a stronger adhesion to the foil metal, the foil surface was pretreated with a phosphating solution. It was found that during heating up the elemental composition of the surface layer of the Kh15Yu5-alloy foil does not remain constant and depends on the mode of thermal effect. This implies the possibility of changing the adhesion and adsorption properties of the foil surface, as well as the need to take this into account when depositing secondary support and an active phase to the foil. Studies have shown that the applied methods for phosphatizing and depositing secondary support to the foil surface make it possible to obtain a quite resistant coating. No peeling of the secondary support from the foil surface is observed during high-temperature treatment in the air.

Influence of various thermal conditions on the composition of high‑temperature diffusion oxides (satellite inclusions) in solid steel

The main goal of any modern production of long products is to ensure the required quality of finished products. One of the important quality indicators, along with mechanical and technological properties, is the quality of the rolled metal surface. The article presents the results of experimental studies of the composition of high‑temperature diffusion oxides formed on the surface of artificially deposited defects under various conditions of temperature exposure using the microrentgenospectral method on a scanning electron microscope with an energy dispersive microanalyzer. The characteristic features in terms of the percentage and presence of certain chemical elements in the scale of various steel grades have been established.

The zinc Lysinate-riboflavinate structure colloid particles are a kind of colloid particles

Zinc Lysinate-riboflavinate is a new improved form of zinc that could be used to enrich whole milk products. This paper presents the findings of a study of the zinc Lysinate-riboflavinate phase composition. Its space group and crystal lattice type have been determined. The microstructure of zinc Lysinate-riboflavinate was investigated, and it was discovered that the samples are needle-shaped crystals with lengths ranging from hundreds of nanometers to several microns. Energy-dispersive microanalysis was used to determine the elemental composition of the material.

Evidence of Surface Properties by Isopropanol Decomposition Reaction and NH3‐TPD over Ni−Fe Spinel Nanoparticles Prepared via Hydrothermal Route

AbstractIn this work, surface properties evaluated by catalytic conversion of isopropanol and by ammonia Temperature Programmed Reduction (NH3‐TPD) over ferrite spinel nanoparticles was investigated. Bulk NiFe2O4 with specific surface area 114 m2/g and crystallites size 6 nm was prepared by hydrothermal synthesis using nitrates as precursors. X‐ray diffraction (XRD), Raman spectroscopy, specific surface area by B.E.T, Scanning Electron Microscopy (SEM) and X‐ray energy dispersive microanalysis (EDS), Transmission Electron Microscopy (TEM) and X‐ray Photoelectron Spectroscopy (XPS) techniques were used for their structural and textural characterizations. The reducibility by hydrogen at variable temperatures was investigated by Temperature Programmed reduction (H2‐TPR) and Thermal Gravimetric Analysis‐ Differential Scanning Calorimetry (TGA‐DSC). The total acidity and acid strength distribution was determined by NH3‐TPD. The synthesized oxide showed the presence of mixed phases containing the inverse spinel structure NiFe2O4 as the major phase and iron oxide α‐Fe2O3 as an additional phase. It was shown that the surface of the powder was richer in Ni2+ species. The surface acidity (Brönsted and Lewis) determined by NH3‐TPD showed that the number of acidic sites increased dramatically with the temperature. The catalytic conversion of isopropanol yields both acidic and redox/basic sites were available. A good correlation between textural, structural, redox and acid‐base properties of catalyst is established.