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Marta V. Yarmolich

Marta V. Yarmolich
Scientific-Practical Materials Research Centre of the National Academy of Sciences of Belarus · Cryogenic Research Division

PhD

About

42
Publications
3,132
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203
Citations

Publications

Publications (42)
Article
Using combined synthesis modes and optimized conditions for ultrasonic dispersion, we obtained a single-phase nanosized Sr2FeMoO6–δ powder having a high degree of superstructural ordering of Fe and Mo cations (88%) and an average grain size of 70.8 nm. The results of the Mössbauer spectroscopy and magnetic measurements show that the obtained nanosi...
Article
We report our systematic investigation of structural, magnetic, and magnetocaloric properties of double perovskite compounds Ho2FeMnO6, Ho2CoMnO6, and Ho2NiMnO6, which crystallize into monoclinic crystal structure with P21/n space group. The magnetic phase transition temperatures are determined to be 7.5 K for Ho2FeMnO6, 69 K for Ho2CoMnO6, and 71....
Article
Full-text available
Double perovskite ceramics Sr2FeMoO6−δ having different amount of antisite disordering and oxygen content are prepared by the solid-phase reaction method using SrFeO2.52(3) and SrMoO4 initial reagents. X-ray and neutron diffraction techniques are used to estimate a modification in the structural parameters as a function of oxygen content and B-site...
Article
The heat capacity and magnetisation of the obtained by the solid-phase method from simple oxides single-phase compound Ba2FeMoO6-δ, in which the superstructural ordering of Fe and Mo cations occurs, was studied. The anomalous behaviour of the temperature dependences of heat capacity (deviation from Debye T³ law) and magnetic moment (ZFC mode) is in...
Article
This work is a contribution to the understanding of the electrical resistivity in strontium ferromolybdate (Sr2FeMoO6-δ, SFMO) ceramics. It demonstrates that an appropriate thermal treatment leads to the formation of dielectric SrMoO4 shells at the surface of SFMO nanograins. In samples without SrMoO4 shells, the sign of the temperature coefficient...
Article
The present paper is devoted to the study of the structural degradation mechanisms of ferroelectric having Pb1−хBaхZr0,53Ti0,47O3−δ composition. On the base of investigations of the influence of temperature-time synthesis modes on the structural perfection degree of the Pb0,85Ba0,25Zr0,53Ti0,47O3−8 compound, it has been determined, that a shift of...
Article
Sr2FeMoO6–x polycrystalline samples with different oxygen content (6−x) and various degrees of superstructural ordering of Fe/Mo cations (P) were obtained by the solid-phase method from the SrFeO2.52 and SrMoO4 precursors. From the investigation on the influence of oxygen non-stoichiometry and the P parameter on the magnetic properties of Sr2FeMoO6...
Article
The sequence of phase transformations during the crystallization of SrBaFeMoO6–δ by the solid-phase technique from a stoichiometric mixture of simple oxides SrCO3 + BaCO3 + 0.5Fe2O3 + MoO3 was studied. It has been established that the synthesis of barium – strontium ferromolybdate proceeds through a series of sequential - parallel stages. It was fo...
Article
Full-text available
Single-phase Sr 2 FeMoO 6-δ samples with different-degreesuperstructiral ordering Fe/Mo cations superstructural ordering (P, 76, 86 and 93 %) were obtained by the solid-phase technique. Based on the results of measuring the magnetic characteristics in the samples, we found that an increase in magnetization (26.41, 32.36 and 42.66 A·m ² ·kg –1 ), ma...
Preprint
Full-text available
This work is a contribution to the understanding of the electrical resistivity in strontium ferromolybdate (SFMO) ceramics. It demonstrates that an appropriate thermal treatment leads to the formation of dielectric SrMoO4 shells at the surface of SFMO nanograins. In samples without SrMoO4 shells, the sign of the temperature coefficient of resistanc...
Article
Full-text available
Nanoporous anodic alumina matrices have been used by Gennady Gorokh et al. (article number 1900283) as templates for the deposition of multicomponent metal oxide films of various compositions. The cover shows 12 electron microscopic images illustrating different types of the cellular‐porous structure morphology of the anodic alumina matrices, some...
Article
Full-text available
The kinetics of phase contents modification in the process of SrBaFeMoO 6–δ crystallization from a stoichiometric mixture of SrCO 3 + BaCO 3 + 0,5Fe 2 O 3 + MoO 3 simple oxides using the solid phase method has been investigated. In the temperature region of 300–1200°С, a number of endotermic effects have been detected. Herewith, the first one (with...
Article
The activation energy of oxygen diffusion in strontium ferromolybdate Sr2FeMoO6–δ is determined by the Merzhanov technique based on the temperature dependences of the oxygen desorption dynamics. The activation energy has a minimum value of 76.7 kJ mol−1 at δ = 0.005 and a maximum value of 156.3 kJ mol−1 at δ = 0.06. It is suggested that with an inc...
Article
Low‐profile anodic alumina matrices 1 µm thick with pore sizes of 105 and 160 nm were formed by two‐step anodizing of Al layers on Si substrates and then the formed alumina matrices were used as templates for deposition of multicomponent metal oxide films on their surfaces. The metal oxide systems of Sr2FeMoO6–δ, Fe x MoyOz and Sn x MoyOz composite...
Article
Full-text available
The sequence of phase transformations in the process of crystallization of the Sr 2 CrMoO 6 by the solid-phase technique from a stoichiometric mixture of simple oxides SrCO 3 + 0.5Cr 2 O 3 + MoO, has been investigated. It was determined that the synthesis of the strontium chrome-molybdate proceeds through a series of sequential-parallel stages. By...
Article
Full-text available
Single‐phase strontium ferromolybdate (Sr2FeMoO6–δ) samples with different degrees of the superstructural ordering of the Fe/Mo cations (P) are obtained from partially reduced SrFeO3–х, SrMoO4 precursors by the solid‐state technology. The study of the temperature dependences of the magnetization measured in the field‐cooling and zero‐field‐cooling...
Article
The use of porous templates for controlled formation of nanostructures and nanosystems requires reliable method of pore size, shape, quantity per unit area (porosity), distance to nearest neighbors and porous matrix thickness monitoring. The scanning electron microscopy method allows to estimate these parameters, however, manual processing of obtai...
Article
Single‐phase Sr2FeMoO6−δ powders with various oxygen indices (δ) and degrees of the superstructural ordering (P) of the Fe/Mo cations are obtained from SrFeO2.52 and SrMoO4 reagents via solid‐state synthesis. It has been established by means of the X‐ray and neutron diffraction that, upon reducing the oxygen content and enhancing the superstructura...
Article
Full-text available
The single-phase strontium ferromolybdate powder with the double perovskite structure has been synthesized by the citrate-gel method with superstructural ordering of iron and molybdenum cations of 88%. The formation of the SrMoO4 phase on the intergrain boundaries has been determined by means of the XRD studies, the Electrokinetic Sonic Analysis te...
Article
Full-text available
Magnetic metal-oxide compounds with high values of magnetoresistance (MR) have attracted huge interest for spintronic applications, among which Sr2FeMoO6-δ (SFMO) has been relatively less known compared to the cobaltites and manganites, despite 100% electrons spin-polarization degree and a high Curie temperature. Here, stable fabrication and system...
Article
Full-text available
The behavior of the crystalline and magnetic structure of Ba 2FeMoO 6 compound in a wide pressure range from 0 to 4.7 GPa was studied. The crystal structure of ceramic sample was described in the framework of SG I4/mmm (No 139) and contains less 10% of anti-site defects. The change of tetragonal structure (I4/mmm) was not observed in all measured p...
Article
Single-phase agglomerated Sr2FeMoO6-δ powders with the iron and molybdenum cations superstructural ordering of 88% were synthesized by sol-gel technique from the Sr(NO3)2 and Fe(NO3)3·9H2O solutions with pH = 4. The ultrasound dispersion enabled us to obtain 75 nm grains. Powders were pressed with 4 GPa to receive the ceramics. The additional annea...
Article
Full-text available
Monophasic iron ferromolybdate nanopowders with a double perovskite structure have been synthesized using the citrate-gel technique at pH=4. A superstructural ordering degree of the iron and molybdenum cations of 88% has been obtained. X-ray diffraction of pressed Sr2FeMoO6−δ pellets subjected to annealing at T=700K and p(O2)=10Pa has revealed the...
Article
We have studied the effect of synthesis conditions on the phase composition, grain size and morphology, degree of superstructural ordering, and magnetic properties of the Sr2FeMoO6–δ double perovskite. The results demonstrate that its magnetic state, dependent on the nonuniformity of grain morphology and the degree of superstructural ordering of th...
Article
Full-text available
The sequence of phase transformations during Sr2FeMoO6-x crystallization by the citrate-gel method was studied for powders synthesized with initial reagent solutions with pH values of 4, 6 and 9. Scanning electron microscopy revealed that the as-produced and annealed powders had the largest Sr2FeMoO6-x agglomerates with diameters in the range of 0....
Article
Electrical transport properties of the YBa2Cu3O7−δ + Sr2FeMoO6−δ superconductor–ferrimagnet composite as a function of the temperature and applied magnetic field are reported. Four different intervals in the temperature dependence of the resistivity have been found between room temperature and 4.2 K. In the temperature range from 300 K down to a se...
Article
Nanosized single-phase powders of the ferrimagnetic double perovskite Sr2FeMoO6–δ (SFMO) with various degrees of the superstructural ordering of the Fe3+ and Mo5+ cations have been synthesized by the citrate–gel method at pH = 4, 6, 9 (samples SFMO 4, 6, and 9). According to the results of the X-ray photoelectron spectroscopy, a mixed valence state...
Article
Full-text available
The metal oxide compounds Sr2FeMoO6-δ systems with an ordered double perovskite structure due to their unique and extremely important magnetotransport and magnetic properties are among the most promising materials for spintronic devices. In the present work, we investigated the correlation between the citrate-gel synthesis conditions (pH of initial...
Article
Full-text available
Investigations of the formation conditions of Sr2FeMoO6−δ compound films, depending on the substrate temperature and sputtering rate with their subsequent thermal treatment, have made it possible to obtain the single-phase homogeneous films. The analysis of x-ray diffractometry and magnetic force microscopy data has made it possible to reveal the s...
Article
A method has been developed for fabricating nanoporous matrices based on anodic aluminum oxide for the deposition of ferromagnetic nanoparticles in them. The modes of deposition of strontium ferromolybdate thin films prepared by the ion-plasma method have been worked out, and the magnetic and magnetoresistive properties, structure, and composition...
Article
Full-text available
We report our investigation on structural and magnetic properties of double perovskite Sr2FeMoO6 (SFMO) films fabricated at different annealing temperatures. Structural properties have been investigated by means of X-ray absorption near-edge spectra and extended X-ray fine structure, where a change of oxidation state has been observed depending on...
Article
Among the group of materials with the double perovskite structure, a half-metallic Sr2FeMoO6 (SFMO) system has attracted increasing attention. Recently, numerous studies have been carried out to understand the structural, magnetic, and magnetocaloric properties of SFMO [1-3] since the SFMO materials have TC about the room temperature, high low-fiel...
Article
Full-text available
We have investigated temperature-dependent magnetic hysteresis loop behavior of Ba 2- x La x FeMoO 6 with double perovskite structure by means of a vibrating sample magnetometer (VSM). As partial substitution of Ba ²⁺ by La ³⁺ is varied from x = 0.1 to 0.3, T C is found to increase from 324 to 345 K. Interestingly, however, hysteresis loop area, re...
Article
Strontium ferromolybdate (Sr2FeMoO6–δ , SFMO) is a material exhibiting promising magnetoresistive properties. We have synthesized SFMO samples out of simple oxides (SrCO3, Fe2O3, and MoO3 or partially reduced SrFeO3–x (SFO) and SrMoO4–y (SMO) precursors. The samples have been experimentally investigated using X-ray diffraction, temperature-dependen...
Article
In this work, the magnetic properties and critical behavior around ferromagnetic-paramagnetic (FM-PM) phase transition in Ba1.7La0.3FeMoO6 compound have been investigated in detail. This compound exhibites a second-order magnetic phase transition with Curie temperature TC = 345 K. The critical exponents β, γ, and δ that are determined by using the...
Article
The forming technique of modified anodic alumina low-profile matrices with precisely controlled dimensions of cellular-porous structure were developed. The vacuum methods of films deposition on to the smooth substrates and porous anodic alumina surfaces were optimized. The structure and composition of nanostructured films was investigated.

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Project (1)
Project
The main goal of the project is the elaboration of research and development principles and technology, as well as creation of novel nanoheterostructures for application in spintronic devices, first of all, in magnetic field sensors and magnetoresistive random access memories. The key research and technological aspects are focused on the formation of layers and/or nanosized grains of a ferromagnetic material with an ultimate degree of conduction electron spin polarization, separated by dielectric interlayers. The main research, technological and innovation aspects of the work are aimed at an increase of the devices’ sensitivity to magnetic fields thanks to the high degree of spin polarization and to the magnetoresistance due to electron quantum tunneling through dielectric barriers. The proposed creation methods of the device prototypes can be rapidly implemented in the automotive, electronic and biomedical industries by means of a rather simple technology, which makes them attractive for the industry across the EU, as only the standard technological equipment is used. The new generation spintronic devices to be developed in the present project will possess high sensitivity, speed performance and low energy consumption. The project aims as well at the creation of a stimulating and interdisciplinary training partnership, with actors from the academia and private sector, promoting the exchange of ideas, methods, techniques as well as enabling an accelerated technology transfer from science to industry through a continuous collaboration between the stakeholders. Working on spintronics demands strongly innovative and interdisciplinary skills, since there is a lot of pressure from the private sector to develop new original solutions for the modern devices. Training of the high-level personnel possessing complementary interdisciplinary skills is thus a key issue.