Papers by Iu. G . Morozov
Molecules
Nitrogen-doped carbon nanomaterial (NDCNM) was synthesized by grinding a mixture of graphene oxid... more Nitrogen-doped carbon nanomaterial (NDCNM) was synthesized by grinding a mixture of graphene oxide and melamine in a planetary mill with both balls and milling chamber of zirconium dioxide. In the electron spin resonance spectrum of NDCNM, a broad signal with g = 2.08 was observed in addition to a narrow signal at g = 2.0034. In the study using a vibrating-sample magnetometer, the synthesized material is presumably a ferromagnet with a coercive force of 100 Oe. The specific magnetization at 10,000 Oe is approximately 0.020 and 0.055 emu/g at room temperature and liquid nitrogen temperature, respectively.
Applied Surface Science, 2009
For the first time, Mössbauer parameters of mixed cubic spinel NiFe2O4 nanoparticles, prepared by... more For the first time, Mössbauer parameters of mixed cubic spinel NiFe2O4 nanoparticles, prepared by using a one-stage process via evaporation of levitating iron-nickel droplets into a mix of helium-air gas flow accompanied with the application of a DC electric field of up to 210 kVm, are reported.
2017 XI International Conference on Antenna Theory and Techniques (ICATT)
This paper considers the problem of formation and optimization of the electromagnetic fields in d... more This paper considers the problem of formation and optimization of the electromagnetic fields in dielectrics, filling a metal cylinder. The results of mathematical modeling of dielectric heating of liquid in the stream are presented.
Pure and aluminum substituted lanthanum ferrites LaFe1−xAlxO3 (x = 0–1.0) were synthesized in air... more Pure and aluminum substituted lanthanum ferrites LaFe1−xAlxO3 (x = 0–1.0) were synthesized in air by self-propagating high-temperature synthesis (SHS) using iron or aluminum as sources of fuel. Two series of samples were produced: I – SHS in the absence of an external magnetic field (zero field SHS); II – SHS in a magnetic field of 0.27 T (applied field SHS); both series of samples were sintered at 1400 °C for 65 h with intermediate grinding. Scanning electron microscopy, energy dispersive analysis of X-rays, X-ray powder diffraction and IR spectroscopy were carried out for both series of samples. XRD showed that for all the combustion products single phase orthorhombic ferrites were produced with a decrease in lattice parameters and unit cell volume with aluminum content (e.g., for series I: x = 0, V = 242.4 A3; x = 1.0, V = 217.3 A3) as well as with magnetic field (e.g., for series I: x = 0.3, V = 233.8 A3; for series II x = 0.3, V = 232.8 A3). 57Fe Mossbauer indicated that at low...
Phase Transitions, 2013
ABSTRACT The paper discusses the fundamentals and the requirements for layer-by-layer manufacturi... more ABSTRACT The paper discusses the fundamentals and the requirements for layer-by-layer manufacturing of three-dimensional porous parts from complex metal oxide systems (piezoceramics PbTi1-xZrxO3; hexaferrites – BaFe12-xCrxO19 and SrFe12O19; spinels – Li0.5Fe2.5-xCrxO4 and high-temperature superconducting ceramics (HTSC) – YBa2Cu3O7-y) and examines the main aspects of the overlapped processes associated with the self-propagated high-temperature synthesis (SHS) and selective laser sinter- ing (SLS). These two techniques presently offered are joined as the original solutions in this external magnetic field. The perovskite phase compositions, morphology, and element distribution of the fabricated samples were analyzed by the X-ray diffraction (XRD), scanning electron microscopy (SEM) equipped the EDX analysis. Optimal regimes for the three-dimensional (3D) parts laser synthesis and some of their electro physical properties were estimated for conducting the concurrent SHS-SLS reactions, both for the case with the applied dc magnetic field and without it.
Journal of Nanoscience and Nanotechnology, 2013
Selective laser sintering (SLS) was used to prepare porous polymer nanocomposites comprising of a... more Selective laser sintering (SLS) was used to prepare porous polymer nanocomposites comprising of a polycarbonate (PC) matrix doped with 30-50 wt% nano Ni or/and 10-30 wt% nano Cu. The electrical conductivity was measured at f = 1 MHz, bias dc voltage 40 V, and 300-400 K. Magnetic measurements were carried out at r.t. in magnetic fields of up to 10 kOe. Temperature dependence of electrophysical properties was studied for 3D samples derived from PC-Cu powders. Magnetic properties were measured for alternating ferromagnetic/non-magnetic layers with Ni and/or Cu core/polymer shell structures. Temperature dependencies for a real part of a dielectric permeability, loss tangent, and magnetization were found to have a hysteresis character. The structure of sintered items was found to depend of external dc magnetic field.
The objectives of these researches were to investigate the technical fundamentals of synthesizing... more The objectives of these researches were to investigate the technical fundamentals of synthesizing high-strength biocompatible medical implants and tissue scaffolds made from nitinol or titanium using of Selective Laser Sintering/Melting (SLS/M). In particular, we had been identify the processing parameters and procedures necessary to successfully laser synthesize multi-material and functionally graded implants: the physical and mechanical properties, microstructure, and corrosion behavior of the resulting structures; the shape memory effect in porous layered nitinol structures made using laser synthesis. The comparative morphological and histological results of Selective Laser Sintering of porous titanium and nitinol implants are presented. Studies are conducted also on primary cultures of dermal fibroblasts and mesenchymal stromal human cells of the 4-18 passages. The principle possibility of long cultivating a bone marrow on the porous carrier-incubator from NiTi and titanium in vitro was determined. Sufficient understanding of laser synthesized titanium and nitinol structures to determine their suitability for future use as implants, resulting in superior tissue to implant fixation and minimally invasive surgical procedures, was developed.
The paper discusses the prospects of layer-by-layer synthesis of porous tissue scaffolds (matrice... more The paper discusses the prospects of layer-by-layer synthesis of porous tissue scaffolds (matrices) of titanium and NiTi (nitinol) as a repository for stem cells. The experiments are performed on primary cultures of human dermal fibroblasts of 4-18 passages. The culture of dermal fibroblasts is obtained from the skin and muscle tissue of 6 to 10-week abortuses with the method of primary explants. The role of surface morphology of porous matrices of these materials in cell adhesion and proliferation is examined in comparison with cast dental titanium. The surface microstructure and roughness are analyzed with optical and scanning electron microscopy before and after experiments in vitro. The elemental analysis is used to determine the biochemical composition of post-experimental porous matrix structures. The results show high chemotaxis of cells to the samples and effect of the matrix composition on the development of cell culture.
Three-dimensional parts with a wide range of properties were synthesized by combining together se... more Three-dimensional parts with a wide range of properties were synthesized by combining together self-propagating high-temperature synthesis (SHS) and selective laser sintering (SLS). Different powder mixtures were investigated for producing piezoceramics, ferrites, and the high-temperature superconductor. Changing the structure, volume fraction, phase, and pore-distribution within the composite optimized the physical properties. The optimum regime for laser synthesis and some of their
ABSTRACT The comparative microstructural analyses and histomorphological studies of tissue reacti... more ABSTRACT The comparative microstructural analyses and histomorphological studies of tissue reactions to porous titanium and nitinol implants synthesized by Selective Laser Sintering (SLS) are presented for a rat model for bone implants. It was discovered that the surface of porous pegs of titanium and nitinol made by SHS/SLS has a significantly favorable structure to the mechanical interlocking with bone and soft tissues. Histological analysis of decalcified paraffin sections after implant removal could only show that trabecular bone structures and marrow cavities were observed around the porous implants. In the connective tissue of the remaining implant beds the following cells: macrophages, fibroblasts, adipocytes and lymphocytes are discernible. It was shown that the nitinol synthesized by combined SHS/SLS technique has a developed and ordered microstructure. Keywords: SHS-selective laser sintering (SLS)-porous implants-histological and morphological analyses-biointegration
The possibility of implementing a reaction of self-propagated high-temperature synthesis of ferri... more The possibility of implementing a reaction of self-propagated high-temperature synthesis of ferrites controlled through selective laser treatment is demonstrated. The conditions of synthesis of barium hexaferrite with a chromium additive and the effect of additional annealing on the results of synthesis are investigated. The three-dimensional ceramic products obtained have sufficiently good consumer properties.
New experimental methods for investigations of phase formation during SHS have been established. ... more New experimental methods for investigations of phase formation during SHS have been established. First experiments using penetrating synchrotron radiation and energy dispersive detectors for different classes of complex inorganic materials were carried out at ESRF (Grenoble, France) and Daresbury (UK). A new and very sensitive thermal imaging method (Thermal Imaging Technique (TIT)) based on continuous registration of the whole combustion process by using highly sensitive IR-camera and software developed by MIKRON Instruments Co. (USA) was used for precise registration of the combustion parameters. SHS was performed on different types of pure and doped complex inorganic materials in pellet and powder form in a range of dc magnetic fields up to 20 T and in electrical field strengths up to ±220 kV/m. The dc magnetic field was applied during the reaction, supplied either by a permanent magnet (transverse, up to 1.1 T) or by an electromagnet (longitudinal, up to 20 T). The dc electrical field was applied along the direction of the combustion wave front propagation. The combined processes of SHS and SLS (Selective Laser Sintering) of 3D articles for different powdered compositions were optimized with laser irradiation power.
A two-dimensional mathematical model has been developed to describe simultaneous self-propagating... more A two-dimensional mathematical model has been developed to describe simultaneous self-propagating hightemperature synthesis (SHS) and selective laser sintering (SLS) of powder compositions. The models applicability is limited by the magnitude of laser irradiation. It allows a comparison to be made between product geometry and the velocity of the laser irradiation spot.
An investigation of the technical aspects of producing sufficiently high strength porous biocompa... more An investigation of the technical aspects of producing sufficiently high strength porous biocompatible medical implants and tissue scaffolds from nitinol or pure titanium using selective laser sintering/melting (SLS/M) is presented. In particular, the necessary ...
ABSTRACT Comparative microanalysis and histological studies of porous titanium and nitinol (NiTi)... more ABSTRACT Comparative microanalysis and histological studies of porous titanium and nitinol (NiTi) implants fabricated by selective laser sintering are carried out. Sintered Ti and NiTi nanoporous structures are developed with grain sizes ranging from dozens to several hundreds nanometer and their formation is discussed. Dependence of the surface morphology of the implant on laser processing parameters (laser power, scanning velocity and beam diameter) is observed by analyzing the fractal-type nanostructure and its self-organization from the nano- to the macro-passing through the microlevel.It is shown that functional characteristics of the synthesized medical implants depend on the pores size distribution and their relative location as well as on the nanostructural morphology of the sintered surface.
Uploads
Papers by Iu. G . Morozov