Values Of Coercive Force Research Articles

Diagnosis of early creep degradation in 12Cr1MoVG steel based on a hybrid magnetic NDE approach

Accurate identification of microstructural degradation that occurs prior to crack coalescence and growth is crucial for continuous online monitoring of creep damage in main stream pipelines. The magnetic non-destructive testing technique is well-established for quantitative property measurement of creep degradation in steels. During the interrupted creep of 12Cr1MoVG steel at 580 ℃ and 110 MPa, the magnetic properties of crept specimens were evaluated using a combination of magnetic hysteresis loop and Barkhausen noise techniques, the microstructural evolution was also examined by means of scanning electron microscopy combined with EBSD method. The microscopic coercive force and Barkhausen noise characteristic values were chosen as the main parameters of diagnosis, as the most sensitive to the microstructural evolution such as dislocations, precipitates and voids, reflects the changes in material condition indicative of early degradation. Besides, these magnetic signatures even can identify the locations that potentially susceptible to future creep damage in the material, which were validated by microhardness measurement, grain misorientation and dislocation density distributions. It suggested that this work could be used as the technical basis for proactive management of material early degradation in the steam pipelines.

Effect of surface microstructure for corrosion resistance and magnetic properties of an amorphous cobalt-based Co-Si-Fe-Cr-Al ALLOY

The surface of an amorphous cobalt-based alloy of nominal composition Co75Si15Fe5Cr4.5Al0.5 was modified by nanostructures at anodizing in an ionic liquid – bis(trifluoromethane sulfonyl)imide 1-butyl-3-methyl- imidazolium. The magnetic (saturation specific magnetization and coercive force) and corrosion (corrosion potential and resistance) characteristics of an amorphous alloy before and after electrochemical modification of the surface by nanostructures are compared. Modification of the alloy surface partially changes its magnetic properties. After corrosion tests, an increase in the value of coercive force is observed. Corrosion tests were carried out by the method of polarization curves in Ringer’s solution. The corrosion resistance of alloys modified by oxide nanostructures is higher than the corrosion resistance of a polished alloy. The increase in corrosion resistance is mainly determined by the presence of nanostructures.

Structural, magnetic, optical, and antibacterial properties of Mn1-xNixFe2O4 nanoparticles

Herein, we report the synthesis of Mn1-xNixFe2O4 (MNFO) nanoparticles (NPs) with lime peel and capsicum coating for different compositions (x = 0.0–0.4) by chemical co-precipitation method tested for antibacterial properties. The coated sample, Mn0.6Ni0.4Fe2O4 NPs has exhibited excellent antibacterial activity against gram positive and negative species compared to uncoated ones. Significantly, lime peel coated samples have exhibited more antibacterial effect as compared to capsaicin coated at x = 0.4. The crystallite size of the sample analysed via X-ray diffraction (XRD) is in nano regime, 7–10 nm. Results show considerably low strain for all samples except a peak value for composition at x = 0.1; which can be ascribed to the cation distribution and different ionic radii of the bivalent metal ions. Fourier transform infrared spectroscopy (FTIR) confirms presence of functional groups. The ultraviolet visible (UV–Vis) spectra reveal indirect band gap of 2–2.5 eV. The field emission scanning electron microscopy (FESEM) analysis shows nano cubical structure. The energy dispersive x-ray (EDX) spectroscopy confirms the presence of elements (Mn, Ni, Fe, and O) in the sample. The magnetic properties have investigated using vibrating sample magnetometer (VSM), shows saturation magnetization and remnant magnetization decreases with increasing Ni content. The low values of saturation magnetization and coercive force is indicative of formation of soft ferrite with super paramagnetic in nature.

Studying the influence of synthesis conditions on the magnetic properties of perovskite-like YbFeO3 nanomaterials

By using the co-precipitation method, the orthorhombic structure of YbFeO3 (o-YbFeO3) was obtained. To investigate the effect of different synthesis conditions on the resulting samples, NaOH (SH) and (NH4)2CO3 (AC) were used as precipitants, and a temperature range of 750–950 °C (tc) was applied for calcining the as-synthesized products. Depending on the synthesis conditions, the samples can be monophasic or diphasic and exhibit crystalline structure distortion. As the tc increases, the average size of o-YbFeO3 crystallites increases, which is in the 30–60 nm range. The samples' magnetism was not significantly affected by the synthesis conditions, and all displayed paramagnetic behavior, as evidenced by low values of coercive force (0.02–150.01 Oe) and net magnetization (0.41–0.54 emu·g−1); in this regard, the YbFeO3-AC-850 sample appeared to be superior, and the oxygen element preferred to face the sample's surface. The sample's morphology consists of oval-spherical-like grains with high agglomeration.

Preparation of high-performance M-type strontium hexaferrites by ceramic method by optimizing the particle size of raw materials

High-performance strontium hexaferrites (SrM) was prepared by optimizing the particle size of strontium carbonate (SrCO3) and iron oxide (Fe2O3). The microstructure, morphology, particle size and magnetic properties of as-prepared strontium hexaferrite have been examined. The results showed that fine SrCO3 and Fe2O3 powders enhanced reactivity and lowered the starting temperature of the reaction. Magnetic result showed that as-prepared strontium hexaferrite with large saturation magnetization and high coercive force was fabricated by using fine SrCO3 and Fe2O3 powder. The optimum value of saturation magnetization (MS) and coercive force (HC) are 78.97emu/g and 5019Oe respectively. This study facilitated an energy-saving strategy for large-scale production of high-performance strontium hexaferrites in the future.

Nanocomposites Based on Pyrolyzed Polyacrylonitrile Doped with FeCoCr/C Transition Metal Alloy Nanoparticles: Synthesis, Structure, and Electromagnetic Properties.

In the last decade, the development of new materials that absorb electromagnetic radiation (EMR) has received research interest as they can significantly enhance the performance of electronic devices and prevent adverse effects caused by electromagnetic pollution. Electromagnetic radiation absorbers with a low weight and small thickness of the absorber layer, good absorption capacity, and a wide frequency response bandwidth are highly demanded. Here, for the first time, the properties of polymer nanocomposites FeCoCr/C synthesized by doping FeCoCr alloy nanoparticles into a polymer matrix of pyrolyzed polyacrylonitrile are investigated. An analysis of the magnetic properties of FeCoCr/C nanocomposites showed that increasing the synthesis temperature increased the specific magnetization and coercive force values of the FeCoCr/C nanocomposites. The dependence between the ratio of metals in the precursor of pyrolyzed polyacrylonitrile and the electromagnetic and wave-absorbing properties of FeCoCr/C nanocomposites is considered, and the results of complex dielectric and magnetic permeability measurements are analyzed. It is found that the most promising of all the studied materials are those obtained at T = 700 °C with the ratio of metals Fe:Co:Cr = 35:35:30.

(Digital Presentation) Microstructure, Corrosion Resistance, and Magnetic Properties of Amorphous Alloy Co75Si15Fe5Cr4,5Al0,5 before and after Corrosion

Cobalt-based Amorphous Metal Alloys (AMA) can be used as soft magnetic materials in various magnetic devices due to the low value of the natural crystalline magnetic anisotropy. The addition of non-metallic components (Si, B) does not adversely affect the magnetic properties. On the contrary, AMA have high magnetic permeability at low values of coercive force and greater resistance to corrosion compared to crystalline ones.The required important parameters for corrosion description are: the concentration of chloride-ions, the microstructure (especially surface heterogeneity) and the composition of the oxide layer [1]. It was determined that the initial AMA Co75Si15Fe5Cr4.5Al0.5 possesses the low coercive force 0.38 A/m. The modification of the alloy surface with nanostructures by anodizing at different current densities (i) and times in the BmimBF4 ionic liquid (IL) does not affect the value of the coercive force, but its resistance to corrosion in a chloride solution increases. The coercive force increases after corrosion, which may be due to a change in surface morphology.The domain structures of the surface modified with nanostructures and initial alloys are different. After excerption at a constant (i) in IL, the domain structure of the surface consists of relatively large uniformly magnetized regions (Fig. 1a). The coercive force of the sample practically does not change compared to the initial sample.The surface domains after corrosion are broken into smaller ones, while the predominant orientation changes its direction (Fig.1 b). The change in the surface domain structure is accompanied by a significant increase in the coercive force (by a factor of 10), although the maximum magnetic permeability (the slope of the hysteresis loops) does not change.The EIS-tests (electrical impedance spectroscopy) were performed at -200 mV (Ag/AgCl) in the frequency range of 50,000 to 0.01 Hz and an oscillation amplitude of 20 mA in Ringer's solution (Fig.1 c, d) to compare the charge transfer kinetics for modified with nanostructures and initial samples. The simulated equivalent circuit included the values of the solution resistance Rs (22 Ω), the value of the constant phase element CPE associated with the double layer capacity, including the capacitance of the modified surface layer, and Rp is the charge transfer resistance across the interface. The capacity of the double layer is higher for the modified sample (4.28*10-5 Ohm-1*cN vs. 1.88*10-5 Ом-1*сN ) and the resistance value of the material has hardly changed (18000±13.5% Ohm for modified and 15500±3.5% Ohm for unmodified). The values of the phase angle (0.78 - modified and 0.88 - unmodified) indicate a greater heterogeneity of the charge distribution at the boundaries of the double layer for the modified surface of the alloy.So, surface modification affects the corrosion resistance, while it has little effect on the parameters of hysteresis loops, what is very important in practical applications. Nyby, C., Guo, X., Saal, J. E., Chien, S.-C., Gerard, A. Y., Ke, H., Frankel, G. S. (2021). Electrochemical metrics for corrosion resistant alloys. Scientific Data, 8(1).doi:10.1038/s41597-021-00840-y Figure 1

К вопросу о точности определения температуры огневого воздействия по следам пожара

After the fire is extinguished, it is required to study a set of the parameters, the most important of which is the temperature of fire exposure. The material of building metal structures, including hazardous production facilities that are in the zone of high temperatures, is undergoing changes. According to them, the magnitude of the temperature effect is determined, that is, metal structures act as natural thermal witnesses. Currently, the temperature effect is assessed visually by the colors of thin oxide films (tint colors) on the metal structures surface. It is experimentally proven that such an assessment is subjective. Recommendations based on this method cannot be considered sufficiently reliable. The purpose of the conducted study is to determine the effect of temperature loading on the hardness and magnetic properties of the carbon building steels. During heating and subsequent cooling, two synergetically affecting each other processes occur simultaneously in steel: a change in the structure and properties of the base metal, as well as the appearance of oxide films on the surface. It is established that the characteristics of the metal — hardness and coercive force do not correlate with each other in all the temperature ranges of heating. However, each exposure temperature corresponds to only one pair of hardness and coercive force values. Based on the results of the conducted experiments, the method was developed for determining the temperature effect by a complex change in the hardness and coercive force of the steel structures. The proposed method will allow to improve the reliability of expert opinions on the possibility of further operation of the buildings and structures after a fire.

Effect of Bi2O3 contents on magnetic and electromagnetic properties of LiZnMn ferrite ceramics

Soft LiZnMn ferrites with low coercive force values and small grain sizes were developed by the solution combustion synthesis and low temperature sintering technique for microwave applications at a high frequencies. Bismuth oxide was used as an additive to lower the sintering temperature. The examination covered the influence of Bi2O3 on the crystal structure, microstructure, primary magnetic and dielectric characteristics of lithium-zinc-manganese ferrites. The most promising sample designed for using in microwave devices was produced by sintering at 1075 ℃ temperature for 8 h with added 1.5 wt% Bi2O3. These production conditions have yielded 2.98 µm average grain size in a ceramic product, the density is 4.84 cu cm/g, and the coercive force, residual induction, and saturation induction are 58 A/m, 2078.4 G, and 3439.1 G, respectively. In addition, this sample demonstrates a high initial magnetic permeability (μi = 168), Curie temperature (Tc = 437.5 ℃), high values of the dielectric loss tangent (tan δɛ = 6.32⸱10−3), ferromagnetic resonance line width (ΔH = 280 Oe) and the resonance line of spin waves (ΔHk = 1.87 Oe). Further increase in the bismuth oxide content allows observing a change in the ceramics microstructure, accompanied by a deterioration in the magnetic and electromagnetic characteristics. Here, the discussion covers the mechanism of change in the functional properties of lithium-zinc-manganese ferrites produced in the conditions of solution combustion with added bismuth oxide. Thus, synthesizing of initial pre-ceramic powder by glycine-nitrate combustion and subsequent low-temperature sintering with added bismuth oxide is a novel efficient technique of producing advanced soft high-frequency LiZnMn ferrites.

Coercive force of double layer ferromagnetic materials

Peculiarities of the coercive force (CF) measuring of inhomogeneous ferromagnetic materials, in particular layered ones, are considered. The concept of effective CF of layered ferromagnetic materials is introduced. The analysis of the magnetic fluxes distribution in a double layer ferro-magnetic material during its reversal magnetization by an attachable transducer with a U-shaped core made of soft magnetic material is carried out. An analytical expression of the effective CF for such class of materials for the case of the same layers’ thickness and linear approximation of their demagnetization curves is obtained. It was found that the effective CF of a double layer ferromagnetic material is determined not only by the CF of its individual layers, but also by the values of their residual induction. Experimental verification of the obtained results was performed on experimental samples, which were collected from steel 08kp (sample # 1) and steel St3 (sample # 2) plates. Each of the samples was a stack of 6 plates each measuring 87×50×1 mm. With tight compression of the plates and complete elimination of the gaps between them, these samples can be considered as single layer ferromagnetic structures with a thickness of 6 mm. To model a double layer ferromagnetic material with the same layer thickness, sample № 3 was used. Its the upper part consisted of the three steel 08kp plates and the lower part – of the three steel St3 plates. To measure the magnetic parameters of these samples the KRM-Ts-MA type magnetic analyzer was used. The device permit to measure the CF, residual induction and other parameters of the hysteresis loops of ferromagnetic materials in the closed magnetic circuit by attachable type transducers with U-shaped core. The transducer used with the magnetic analyzer during the experiments had poles with an area of 16×32 mm and the distance between the edges of the poles: inner – 32 mm, outer – 64 mm. It is shown that the discrepancy between the calculated value of the effective CF of the double layer ferromagnetic material (sample # 3) from steel 08kp and St3 according to the obtained expression and the measurement results is about 3%. This confirms the adequacy of the proposed model of reversal magnetization of double layer ferromagnetic material and the correctness of analytical calculations.

Boost the Crystal Installation and Magnetic Features of Cobalt Ferrite/M-Type Strontium Ferrite Nanocomposites Double Substituted by La3+ and Sm3+ Ions (2CoFe2O4/SrFe12-2xSmxLaxO19).

Spinel cobalt ferrite/hexagonal strontium hexaferrite (2CoFe2O4/SrFe12−2xSmxLaxO19; x = 0.2, 0.5, 1.0, 1.5) nanocomposites were fabricated using the tartaric acid precursor pathway, and the effects of La3+–Sm3+ double substitution on the formation, structure, and magnetic properties of CoFe2O4/SrFe12−2xSmxLaxO19 nanocomposite at different annealing temperatures were assayed through X-ray diffraction, scanning electron microscopy, and vibrating sample magnetometry. A pure 2CoFe2O4/SrFe12O19 nanocomposite was obtained from the tartrate precursor complex annealed at 1100 °C for 2 h. The substitution of Fe3+ ion by Sm3–+La3+ions promoted the formation of pure 2CoFe2O4/SrFe12O19 nanocomposite at 1100 °C. The positions and intensities of the strongest peaks of hexagonal ferrite changed after Sm3+–La3+ substitution at ≤1100 °C. In addition, samples with an Sm3+–La3+ ratio of ≥1.0 annealed at 1200 °C for 2 h showed diffraction peaks for lanthanum cobalt oxide (La3Co3O8; dominant phase) and samarium ferrite (SmFeO3). The crystallite size range at all constituent phases was in the nanocrystalline range, from 39.4 nm to 122.4 nm. The average crystallite size of SrFe12O19 phase increased with the number of Sm3+–La3+ substitutions, whereas that of CoFe2O4 phase decreased with an x of up to 0.5. La–Sm co-doped ion substitution increased the saturation magnetization (Ms) value and the subrogated ratio to 0.2, and the Ms value decreased with the increasing number of double substitutions. A high saturation magnetization value (Ms = 69.6 emu/g) was obtained using a La3+–Sm3+ co-doped ratio of 0.2 at 1200 for 2 h, and a high coercive force value (Hc = 1192.0 Oe) was acquired using the same ratio at 1000 °C.

THE ROLE OF DEPOSITION TEMPERATURE ON PARTICLE SIZE, ROUGHNESS PARAMETERS, MAGNETIC AND STRUCTURAL FEATURES OF ELECTROCHEMICALLY GROWN Ni–Fe/ITO SAMPLES

In this work, the impact of the deposition temperature (DT) on the particle size, roughness parameters, coercive force, squareness and structural features of the Ni–Fe samples electrochemically deposited onto glasses covered with indium tin oxide (ITO) was researched. An increase in the DT from 20 to 40 °C led to a very slight increase in the Fe concentration of the samples, revealing that the effect of the DT on the chemical composition was insignificant. The crystal structure was a face–centered cubic (fcc) and the preferred growth orientation was in the [111] direction irrespective of the DT. The crystallization of the samples improved, the size of the crystallites increased and the strength of the [111] growth orientation diminished with the DT. An increment in the DT resulted in a strong enhancement in the particle size and surface roughness. Further surface analysis indicated that the sample surface had a well spread out height distribution at the DT of 40 °C, while the sample surfaces at lower DTs 20 and 30 °C had narrow height distributions. In addition to that, the peaks were found to be predominant on the sample surfaces at lower DTs (20 and 30 °C), whereas the deep valleys were predominant on the sample surface at the DT of 40 °C. Magnetic measurements confirmed the existence of a semi–hard magnetic property in all samples. Compared to other samples produced at lower DTs (20 and 30 °C), the Ni–Fe sample electroplated at the DT of 40 °C possessed the highest coercive force and squareness values. Moreover, the magnetic characteristics of the samples were compatible with their morphological and structural characteristics.

THE ROLE OF DEPOSITION TEMPERATURE ON PARTICLE SIZE, ROUGHNESS PARAMETERS, MAGNETIC AND STRUCTURAL FEATURES OF ELECTROCHEMICALLY GROWN Ni–Fe/ITO SAMPLES

In this work, the impact of the deposition temperature (DT) on the particle size, roughness parameters, coercive force, squareness and structural features of the Ni–Fe samples electrochemically deposited onto glasses covered with indium tin oxide (ITO) was researched. An increase in the DT from 20 to 40 °C led to a very slight increase in the Fe concentration of the samples, revealing that the effect of the DT on the chemical composition was insignificant. The crystal structure was a face–centered cubic (fcc) and the preferred growth orientation was in the [111] direction irrespective of the DT. The crystallization of the samples improved, the size of the crystallites increased and the strength of the [111] growth orientation diminished with the DT. An increment in the DT resulted in a strong enhancement in the particle size and surface roughness. Further surface analysis indicated that the sample surface had a well spread out height distribution at the DT of 40 °C, while the sample surfaces at lower DTs 20 and 30 °C had narrow height distributions. In addition to that, the peaks were found to be predominant on the sample surfaces at lower DTs (20 and 30 °C), whereas the deep valleys were predominant on the sample surface at the DT of 40 °C. Magnetic measurements confirmed the existence of a semi–hard magnetic property in all samples. Compared to other samples produced at lower DTs (20 and 30 °C), the Ni–Fe sample electroplated at the DT of 40 °C possessed the highest coercive force and squareness values. Moreover, the magnetic characteristics of the samples were compatible with their morphological and structural characteristics.

Soft magnetic FeCo films produced by green chemistry technique

The saturation magnetizations, local magnetic anisotropy field and coercivity values of FeCo film plated under various processing conditions have been investigated to optimize soft magnetic properties. Herein, we introduce a very promising processing technique based on the electrodeless deposition of FeCo film with carbohydrates as reducing agents. The produced FeCo film demonstrated significantly better saturation magnetization values and less contaminations, compared to those for the sample preparing with conventional reducing agent (sodium hypophosphite). The surface morphology and coercivities of FeCo films are dependent on the iron content and type of reducing agent. The coercive force values range from 12 up to 30 Oe and the saturation magnetization from 150 to 240 emu/g depending on the bath composition and deposition parameters. Maximum of saturation magnetization magnitude is reached for FeCo film with 30% cobalt. The local anisotropy field value of FeCo alloys increases with a decrease in Fe content for all reducing agent types.

Damage evaluation for AISI 304 steel under cyclic loading based on coercive force measurements

The authors present the results of experimental investigations on the damage evaluation of AISI 304 steel under tension and cyclic loading based on coercive force measurements. It was established that kinetics of the coercive force demonstrates descending and ascending sections on the kinetic curve independently on the loading type. The increase of coercive force is caused by the deformation-induced transformation of the paramagnetic austenite into ferromagnetic martensite. The increasing coercive force is observed during the deformation process up to the loss of metal continuity (initiation and propagation of cracks and voids). While the coercive force shows a decreasing tendency due to the loss of metal continuity (stage of crack propagation). In the coercive force monitoring, it is required to pay attention to the variation in the direction of the kinetic curve and not to the absolute values of coercive force. Thus, the coercive force monitoring in the most critical zones of the structural elements allows one to control for the damage accumulation at each stage of crack initiation or propagation.

Effect of Heating Temperature on Magnetic Properties of Fe3O4 Synthesized by Coprecipitation Method

The synthesis of Fe3O4 nanoparticles with iron rock raw materials was carried out using a coprecipitation method. Iron rocks were taken from the Surian village, South Solok of West Sumatera. This research was conducted to utilize local materials and produce low cost, varied magnetic materials to be applied to the electric and electronics industries. Iron sand as a base material was obtained by processing the iron rocks through destruction and extraction. Iron sand that has been extracted is reacted with HCL and NH4OH. Furthermore, the PEG-2000 were added as a template to homogenize and inhibit the growth of particles. Heating temperature variation performed to see the effect of temperature on the magnetic properties of the particles. Heating temperature variations were used at 500 ̊C, 600 ̊C, and 700 ̊C. Phase composition of the samples were confirm using X-ray diffraction method. Characterization of magnetic properties carried out using Vibrating Sample Magnetometer (VSM). The results of magnetic properties show that the saturation magnetization decreases with increasing heating temperature in the range of 32.6883 emu/g, 20,1632 emu/g, and 10.4734 emu/g respectively. The value of coercive force, HC obtained in the range of 13,840 A/m – 19,120 A/m. The results show that Fe3O4 can be used as a magnetic recording material.

Magnetic properties of TPU/NR blends: low loading NiZn and LNR added

Thermoplastic polyurethane and natural rubber blending are able to change the origin properties polymer material. Then, this blend was added with magnetic filler, NiZn at low loading of 1wt% to 5wt%. Other than that, liquid natural rubber (LNR) was also added as compatibilizer. The previous study presented, NiZn ferrite at 3wt% in TPU/NR blend is the optimum filler loading, but LNR was not unbeaten in its role as compatibilizer. The addition of this magnetic filler enhanced the magnetic properties on saturation magnetization and remanence magnetization but decreased the value of coercive force.

Integrated Approach to Determine Operational Integrity of Crane Metal Structure

One of the elements limiting the crane life cycle and affecting the safety of its operation is a metal structure. Currently, there is no single scientifically-based approach to assess the operational integrity of crane metal structures. The paper deals with issues related to the development of an integrated approach to determine the operational integrity of crane metal structures, based on a combination of numerical methods of calculation (the finite element method and boundary states calculation) and magnetic coercive non-destructive control. The research of the influence of the metal chemical composition, its microstructure and the controlled elements thickness on coercive force values have been carried out. In order to take into account these parameters, it is suggested to use certificated experimental samples with variable cross sections. The practical value of the research is to apply the integrated approach that will eliminate the disadvantages of a separate method, complement these methods, increase the objectivity and accuracy of determining the operational integrity of crane metal structures.

Crystal structure and magnetic properties of LaFe1-xNixO3 nanomaterials prepared via a simple co-precipitation method

In this paper, nanostructured Ni-doped LaFeO3 materials were prepared via a simple co-precipitation method involving the hydrolysis of La(III), Fe(III), and Ni(II) cations in hot water with 5% KOH as a precipitating agent. To evaluate the effects of Ni substitution in these products, their structural phases, lattice parameters, crystallite and grain sizes, and magnetic properties were determined. As the Ni content in the LaFe1-xNixO3 (x = 0–0.25) materials increased, the average crystallite size and lattice parameters decreased. Moreover, across the range of Ni-substitution ratios, all magnetic properties correspondingly changed: the coercive force (Hc) value rose from 42.53 to 173.98 Oe. In contrast, the remanent magnetization (Mr) and saturation magnetization (Ms) values decreased from 1.0· × 10⁻2 to 3.8· × 10⁻4 emu g⁻1, and from 0.24· × 10° to 0.74· × 10⁻4 emu g⁻1, respectively. These predictable changes provide a sound foundation for the fabrication and application of magnetic materials based on nanostructured Ni-doped LaFeO3 substrates.

Sensitivity of a Number of Physical Properties to Fixation of the Initial Stages of Aging of Fe–14.5% Mo Alloy

Regularities of the change in physical properties (coercive force, electrical resistance, and internal friction) of the Fe–14.5% Mo alloy depending on temperature and time of aging after tempering from the single-phase area were studied. It was shown that the internal friction possesses the highest sensitivity to fixation of the initial stages of aging as compared with other studied physical properties. Data on physical properties are comparable with the peculiarities of the phase-structural transformations observed during aging. The aging modes providing the highest values of the coercive force, which limits the practical value of the studied alloy as a high-coercivity material with the average magnetic energy value, were established.