Қазақ ұлттық қыздар педагогикалық университеті / Казахский национальный женский педагогический университет

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  • Некоторые метрики заблокированы вашими 
    Тип записи:Публикация,
    Synthesis of New Complex Ferrite Li0.5MnFe1.5O4, Chemical – Physical and Electrophysical Research
    In this article, the sol-gel method was used as a synthesis method, which shows the physico –chemical nature of the synthesis of a new complex material ferrit Li0.5MnFe1.5O4. The synthesized structure and structure were determined by the method of X-ray phase analysis. According to the analysis indicators, it was found that our compound is single-phase, spinel-structured, and syngony - cubic type. The microstructure of the compound and the quantitative composition of the elements contained were analyzed under a scanning electron microscope (SEM). Through a scanning electron microscope, Microsystems were taken from different parts of l Li0.5MnFe1.5O4-type crystallite, the elemental composition of crystals was analyzed, and the general type of surface layer of complex ferrite was shown. As a result, the fact that the compound consists of a single phase, the clarity of its construction was determined by the topography and chemical composition of the compound. As a result, it was found that the newly synthesized complex ferrites correspond to the Formula Li0.5MnFe1.5O4. The particles of the formed compounds have a large size (between 50.0 μm, 20.0 μm and 10.0 μm). Electro physical measurements were carried out on the LCR - 800 unit at intervals of 293-483 K and at frequencies of 1.5 and 10 kHz. The increase in frequency to 10 kHz led to a decrease in the value ε in the range of the studied temperature (293-483 K).
    Цитирования (OpenAlex) 1
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    Тип записи:Публикация,
    Synthesis and magnetic properties of Y0,5Ca0,5Cr0,5Mn0,5O3 compounds
    In this work,a solid solution of chromite-manganite of the composition Y0,5Ca0,5Cr0,5Mn0,5O3 was synthesized using the sol-gel method. Based on the results of experimental studies of the magnetostatic properties of the polycrystalline system Y0,5Ca0,5Cr0,5Mn0,5O3. It is found that the predominant is the intracrystalline ferromagnetic interaction, while the intercrystalline interaction is antiferromagnetic in nature.In the field of 2000 Oe and 5000 Oe at a temperature of 5 K, the magnetic moment is not even positive. These dependencies were obtained after the sample was in a large negative field. This initial moment is approximately equal to the residual moment on the hysteresis loop for a temperature of 5 K. When the external field is increased gradually, for example, in increments of 250 Oe, this moment increases to 1.2 emu/g at 2000 Oe. Based on the results of magnetostatic measurements, it was found that hysteresis loops of magnetization are observed at low temperatures.
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    Тип записи:Публикация,
    Multifaceted Characterization and Thermal Stability of Y0.5Sr0.5Cr0.5Mn0.5O3 Chromite-Manganite Synthesized via Sol-Gel
    We studied the thermal stability and many-sided properties of Y 0 .5 Sr 0 .5 Cr 0 .5 Mn 0 .5 O 3 chromite-manganite that was made using the sol-gel method.We focused on the syngony type, unit cell parameters, and x-ray analysis.To con􀅫irm the results of the chromite-manganite indexing, the inverse values of the squares of interplane distances (104/d2) and the consistency of the x-ray and pycnometric densities were found to be very close to each other.It was found that the synthesised chromite-manganite crystallises in orthorhombic syngony and has a perovskite-like structure.Scanning Electron Microscopy (SEM) shows that chromite-manganite is uniformly distributed, and the crystallites are sized between 6 and 20 microns.The analysis of the relationship between heat capacity and temperature using the Thermo Gravimetry Analysis (TGA) technique demonstrates the stability of the internal structure and the presence of polymorphic transformations in the sample under study.
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    Тип записи:Публикация,
    Synthesis and physico –chemical characteristics of complex ferriteCrNaFe2O5
    The article discusses for the first time the synthesis, radiographic and electron microscopic examination of CrNaFe2O5, synthesized using the high – temperature Sol-gel method. The phase of complex ferrites was synthesized using Sol-Gel synthesis method at high temperature. Initially, the structure of CrNaFe2O5 composite ferrite was researched by X-ray phase analysis and SEM, the syngony type, elementary cell parameters, radiographic and pycnometric densities and elemental analysis were defined: CrNaFe2O5 -а=5.0289, в= 5.0289, с=13.6938 Å , ρx-ray.= 5.327 g/sm3 , ρpycn.=5.331 g/sm3. A comparative analysis of the connection between the parameters of the Crystal cell of the initial materials and of the obtained complex ferrites was carried out. Through a scanning electron microscope, microsystems were taken from different parts of CrNaFe2O5 type crystallite, the elemental composition of crystals was analyzed, and the general type of surface layer of complex ferrite was displayed. As a result, the fact that the compound consists of a single phase, the clarity of its construction was determined by the topography and chemical composition of the compound. Consequently, it was discovered that the newly synthesized complex ferrites correspond to the formula CrNaFe2O5. The particles of the formed compounds have a large size (between 200 µm, 20.0 µm and 5 µm). The results of the element analysis show that the compound is compatible.
    Цитирования (OpenAlex) 3Цитирования (OpenCitations) 2
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    Тип записи:Публикация,
    Synthesis and structure of polycrystals MnCo2O4-GdCrO4
    The article discusses the synthesis and structure of polycrystalline nanocomposite MnCo2O4-GdCrO4 material. The sol-gel method was used as a synthesis of the study. Using X-ray phase analysis (XPA), the structure of the synthesized nanomaterial composition was determined: spinel – cobalt manganate and perovskite – gadolinium chromite. Based on the results of the analysis, it was established that the polycrystalline two-phase composite is a system of spinel-cubic and perovskite-tetragonal types. Morphological analysis of the nanocomposite was carried out using a scanning electron microscope (SEM). According to the data obtained as a result of SEM, the elemental composition was confirmed and the average nanosize of the nanomaterial was obtained, and the content of the compound increased to x2000 was determined, the particle size of MnCo2O4 is 383-281 nm, GdCrO4 – 1.63-1.34 µm; increased to x4000, particle size – MnCo2O4 277-219 nm, GdCrO4 – 1.48-1.27 µm; increased to x6000, particle size – MnCo2O4 239-209 nm, GdCrO4 –1.21-1.07 µm.
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    Тип записи:Публикация,
    Synthesis of New Complex Ferrite Li0.5MnFe1.5O4: Chemical–Physical and Electrophysical Research
    In this article, the sol–gel method was used as a synthesis method, which shows the physicochemical nature of the synthesis of a new complex material, ferrite Li0.5MnFe1.5O4. The structure and composition of the synthesized ferrite were determined by X-ray phase analysis. According to analysis indicators, it was found that our compound is a single-phase, spinel-structured, and syngony-cubic type of compound. The microstructure of the compound and the quantitative composition of the elements contained within it were analyzed under a scanning electron microscope (SEM). Under a scanning electron microscope, microsystems were taken from different parts of Li0.5MnFe1.5O4-type crystallite; the elemental composition of crystals was analyzed; and the general type of surface layer of complex ferrite was shown. As a result, given the fact that the compound consists of a single phase, the clarity of its construction was determined by the topography and chemical composition of the compound. As a result, it was found that the newly synthesized complex ferrites correspond to the formula Li0.5MnFe1.5O4. The particles of the formed compounds have a large size (between 50.0 μm or 20.0 μm and 10.0 μm). Electrophysical measurements were carried out on an LCR-800 unit at intervals of 293–483 K and at frequencies of 1.5 and 10 kHz. An increase in frequency to 10 kHz led to a decrease in the value ε in the range of the studied temperature (293–483 K).
    Цитирования (OpenAlex) 4Цитирования (OpenCitations) 4
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    Тип записи:Публикация,
    Novel Spinel Li–Cr Nano-Ferrites: Structure, Morphology, and Electrical/Dielectric Properties
    (Multidisciplinary Digital Publishing Institute, 2025-10-26) ; ; ; ;
    This article reports on the synthesis and physicochemical characterization of a novel complex ferrite material, LiCr3.4Fe1.6O8, prepared via the sol-gel method. X-ray diffraction (XRD) analysis confirmed that the synthesized compound is a single-phase material with a spinel-type structure and cubic symmetry. Raman spectroscopy was employed to investigate the vibrational modes, and the observed peaks corresponding to Fe–O and Cr–O bonds further validated the spinel-like structure of the compound. The microstructure and elemental composition were examined using scanning electron microscopy (SEM). Multiple regions of the LiCr3.4Fe1.6O8 crystals were analyzed, revealing a homogeneous phase and providing detailed insight into the morphology and chemical composition of the surface. The synthesized ferrite particles exhibited relatively large dimensions, with sizes measured at approximately 5, 30, 100, and 200 μm. The dielectric behavior was studied to assess the material’s response to an external electric field, demonstrating its capacity for electric charge polarization. Both capacitance and electrical conductivity were found to increase with rising temperature. Electrophysical measurements were conducted using the LCR-800 system over a temperature range of 293–483 K and at frequencies of 1.5 kHz and 10 kHz. An increase in frequency to 10 kHz resulted in a decrease in the dielectric constant (ε) across the entire temperature range.
    Цитирования (OpenAlex) 3Цитирования (OpenCitations) 1
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    Тип записи:Публикация,
    Structure Property–Application Relationships of Spinel Ferrite Nanoparticles: From Synthesis to Functional Systems
    (Multidisciplinary Digital Publishing Institute, 2026-02-24) ; ; ; ;
    Krishnamoorthy Ramachandran
    ). The physicochemical principles, advantages, and limitations of various synthesis techniques-including co-precipitation, combustion, sol-gel, thermal decomposition, hydrothermal, solvothermal, microwave-assisted, sonochemical, electrochemical, and solid-state reaction methods-are comparatively discussed. The influence of synthesis parameters on crystal structure, morphology, and cation distribution between tetrahedral and octahedral sites, as well as on magnetic, dielectric, and optical properties, is critically analyzed. Furthermore, the capabilities of characterization techniques such as X-ray diffraction (XRD), scanning electron microscopy with energy-dispersive spectroscopy (SEM/EDS), Fourier-transform infrared spectroscopy (FTIR), FT-Raman spectroscopy, dielectric measurements, and magnetic measurements for investigating spinel ferrites are comprehensively summarized. Finally, the high potential of spinel ferrite nanoparticles for applications in electronics, microwave devices, water treatment, catalysis, sensors, and biomedical fields is highlighted.
    Цитирования (OpenAlex) 28
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    Тип записи:Публикация,
    Perovskite Manganites: An Overview of Synthesis, Classification, Characterization, and Applications
    Perovskite manganites (AMnO3) and perovskite-like manganites (A′1−xAxMnO3) are complex oxide materials that have attracted significant attention from the scientific community in recent years due to their structural flexibility, mixed-valence state, tunable electronic configuration, and multifunctional properties. This review systematically analyzes the synthesis methods, structural classification, and physicochemical characterization of perovskite manganites, as well as their magnetic, optical, electrical, dielectric, and catalytic properties. The influence of solid-state reactions, sol–gel, Pechini, hydrothermal, co-precipitation, microwave, and other mild chemical approaches on phase purity, morphology, particle size, and oxygen stoichiometry was examined. The structural diversity of perovskite and perovskite-like manganites, including simple ABO3, double perovskites, multilayer, and low-dimensional systems, was characterized in relation to their functional properties. The review discussed the capabilities of methods for synthesizing and analyzing morphological properties, demonstrating the role of doping, cation substitution, oxygen vacancies, and Jahn–Teller distortions in controlling material properties. Prospects for the application of perovskite manganites in spintronics, magnetocaloric cooling, photocatalysis, gas-sensing devices, and energy conversion and storage systems were analyzed. This review highlights the structure–property–application relationship in perovskite manganites.
    Цитирования (OpenAlex) 2