A5064200365- Chemical Synthesis and Characterization
- Crystal Structures and Properties
- X-ray Diffraction in Crystallography
- Bone Tissue Engineering Materials
- Thermal and Kinetic Analysis
- Crystallization and Solubility Studies
- Zeolite Catalysis and Synthesis
- Nuclear materials and radiation effects
- Luminescence Properties of Advanced Materials
- Solid-state spectroscopy and crystallography
- Pigment Synthesis and Properties
- Advancements in Battery Materials
- Graphene and Nanomaterials Applications
- Inorganic Chemistry and Materials
- Inorganic Fluorides and Related Compounds
- Thermal Expansion and Ionic Conductivity
- Metal-Organic Frameworks: Synthesis and Applications
- Polymer Synthesis and Characterization
- Microwave Dielectric Ceramics Synthesis
- Crystal structures of chemical compounds
- Magnetic and transport properties of perovskites and related materials
- Glass properties and applications
- Advanced Condensed Matter Physics
- Advanced Battery Materials and Technologies
- Extraction and Separation Processes
Taras Shevchenko National University of Kyiv
2013-2024
The regularities of nickel- and carbonate-containing calcium phosphates formation were investigated in an aqueous solution the system Сa2+ - Ni2+ PO43- CO32- NO3- at molar ratios : PO43-: = (10-х-у/2) х (6-у) у, (for values x 0.05, 0.1, 0.5, 1.0; у 0 or 0.5) room temperature with their subsequent heating to a 600 °С for 2 hours. conditions biphasic (a mixture phases based on Са10(РО4)6(ОН)2 β-Са3(РО4)2) as well monophasic apatite-related established. crystallite sizes phosphate synthesized...
Detonation-produced hydroxyapatite coatings were studied by scanning electron microscopy (SEM), X-ray powder diffraction (XRD), Raman spectroscopy, and paramagnetic resonance (EPR) spectroscopy. The source material for detonation spraying was a B-type carbonated powder. consisted of tetracalcium phosphate apatite. ratio depended slightly on the degree crystallinity initial processing parameters coating preparation. phase homogeneous; apatite contained defects localized sixfold axis...
The results of calcium phosphates formation in an aqueous solution Сa2+-Mg2+-Na+-PO43--CO32--NO3– systems at different molar ratios Сa2+:Mg2+:Na+:PO43-:CO32– = (10-х-y/2–z/2) : х y (6-z) z, (x 0.25, 0.5, 0.75; у 0.75, 1.0; z 1.0) a temperature 25°С with subsequent heating 600°С for 2 hours are presented. In the case system 5.5 0.5 x 0.25 regardless amount sodium cations (y 0.25–1.0), modified apatite-type (hexagonal system, space group Р63/m) were obtained. For fixed content 0.25), increase...
Abstract In this paper, we propose a new approach for the preparation of sodium‐ and carbonate‐substituted apatite by wet precipitation method in aqueous media at 23 °C. The main difference between conventional techniques is that poorly crystalline calcium phosphates are obtained then heated to form apatite. thermal transformations samples temperature range 80–1000 °C have been determined temperature‐programmed desorption mass spectroscopy thermogravimetry. chemical phase compositions...
The great interest in developing efficient and stable bifunctional electrodes for electrocatalytic water splitting is due to the rapid growth demand sustainable renewable energy sources. Here, we present an original electrode design strategy which can be used oxygen evolution reaction (OER) hydrogen (HER). This based on direct formation of active catalytic material surface during electrolysis. In our case, cobalt hydroxides (β-Co(OH)2 CoO(OH) HER OER, respectively) a carbon matrix are...
A new approach for the preparation of nanoscale copper‐ and zinc‐containing sodium‐ carbonate‐substituted apatites is presented. The thermal transformations samples in temperature range 80–1000 °C were determined by temperature‐programmed desorption mass spectroscopy thermogravimetry. chemical phase compositions studied atomic absorption X‐ray diffraction, respectively. degree nature carbonate substitution elemental analysis (C, H, N) infrared spectroscopy, In addition, scanning electron...
Herein, the peculiarities of complex phosphate formation in self-fluxes Cs-MII-Bi-P-O (MII = Ca, Sr, Ba and Pb) systems with Cs/P 0.7-1.3 at fixed ratios Bi/P 0.2 Bi/MII 1.0 were studied discussed. Three novel isostructural diphosphates general composition Cs3MIIBi(P2O7)2 Sr original framework topology synthesized characterized via single-crystal powder X-ray diffraction, SEM, DTA, FTIR- UV-VIS-spectroscopy. In addition, electronic structure (DFT) Voronoi-Dirichlet polyhedra (VDP)...
Abstract Nanoparticles (25–50 nm) of chemically modified calcium phosphates Ca 10− x − y M ii Na (PO 4 ) 6− z (CO 3 (OH) 2 (M – Cu 2+ , Zn were synthesized via a wet precipitation method at room temperature. The Fourier-transform infrared spectroscopy data confirmed the partial substitution <m:math xmlns:m="http://www.w3.org/1998/Math/MathML"> <m:msubsup> <m:mrow> <m:mtext>PO</m:mtext> </m:mrow> <m:mn>4</m:mn> <m:mn>3</m:mn> <m:mo>−</m:mo> </m:msubsup> </m:math> {\text{PO}}_{4}^{3-} →...
Nonacalcium chromium(III) heptakis(orthophosphate) has been obtained from a melt in the system Cs2O–CaO–Cr2O3 using polyphosphate flux. The three-dimensional framework is related to whitlockite structure [β-Ca3(PO4)3] and built up CaO8 CaO9 polyhedra sharing vertices, edges faces, further connected by PO4 tetrahedra CrO6 octahedra. Cr, one P O atom are located on threefold rotation axes. Ca9Cr(PO4)7 isotypic with Ca9Fe(PO4)7. crystal studied was an inversion twin.
Polycrystalline silver(I) decacalcium heptakis(orthophosphate), AgCa10(PO4)7, was obtained by solid-state reaction. It is isotopic with members of the series MCa10(PO4)7 (M = Li, Na, K and Cs), closely related to structure β-Ca3(PO4)2. The crystal title compound built up from a framework [CaO9] two [CaO8] polyhedra, one [CaO6] octahedron (site symmetry 3.) three PO4 tetrahedra (one site 3.). Ag+ cation likewise located on threefold rotation axis resides in cavities rigid [Ca10(PO4)7]−...
Abstract The interaction of TiN with Na 2 O–K O–P O 5 melts was investigated at (Na+K)/P molar ratios 0.9, 1.0, and 1.2 Na/K 1.0 2.0. Interactions in the system led to loss nitrogen partial phosphorus resulted formation KTiP 7 langbeinite‐type K 2− x Ti (PO 4 ) 3 ( x= 0.22–0.26) solid solutions over temperature range 1173 1053 K. phase compositions obtained samples were determined by using X‐ray diffraction (including Rietveld refinement), scanning electron microscopy (using...
The particularities of the chemical interaction in systems M I PO 3 ‐M II O(or Mn 2 O )‐ Cl ( – Na, K; Mg, Co, Ni, Zn) have been investigated at temperature 1073 K and molar ratios P/ x = 1 or Cl/( + )) 30. conditions formation complex phosphates І 4 Na Ni (PO ) P 7 found. Influences nature alkali bivalent metals on products composition were discussed. advantages chloride melts using (synthesis time reduction reducing) for preparing shown. synthesized compounds characterized powder X‐ray...
Abstract The crystallization of alkali‐earth phosphates in the melts Cs 2 O‐P O 5 ‐M II (M – Ca, Sr, Ba) pseudo‐ternary systems have been investigated at various Cs/P molar ratios and fixed value M /P equal to 0.15. Type phosphate which crystallizes depends on initial ratio. Crystallization fields CsM P 3 9 , 7 were briefly characterized. new diphosphate CaP has obtained by single crystal powder X‐ray diffraction FTIR‐ spectroscopy. It C 2/m space group, with following parameters monoclinic...
Caesium magnesium orthophosphate is built up from MgO(4) and PO(4) tetra-hedra (both with . m. symmetry) linked together by corners, forming a three-dimensional framework. The Cs atoms have .m. site symmetry are located in hexa-gonal channels running along the a- b-axis directions.
Abstract Exploring the effect of isomorphic substitution atoms on crystal structure and features oxide compounds is one main tasks modern materials science. This paper deals with La/Sm isovalent in a two-slab perovskite-like BaLa 2 In O 7 its structural magnetic properties 2− x Sm indates synthesized. A complete characterization including data scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), diffraction (XRD), calculations (Rietveld method), second optical...
The interaction in the molten system Rb 2 O‐P O 5 ‐TiO ‐NiO was investigated at different molar ratios Rb/P = 0.5‐1.3, fixed Ti/P 0.15, Ti/Ni 1.0 temperature range 1073–953 K. conditions of formation complex phosphates RbTi (PO 4 ) 3 , Ni 0.5 Ti 1.5 and RbNiPO have been determined. new phosphate (space group P 1 3, a 9.9386(2) Å) has obtained by single crystal X‐ray diffraction FTIR‐spectroscopy. It langbeinite‐like structure, that is built up from mixed (Ni/Ti)O 6 ‐octahedra РО ‐tetrahedra....
Crystallization of high temperature self‐flux system Na 2 O‐K O‐TiO ‐P O 5 was investigated at different molar ratios (Na+K)/P = 0.9; 1.0 or 1.2 and Na/K 2.0 over the range 1000–650°C. The conditions formation complex phosphates K 0.10 0.90 Ti (PO 4 ) 3 (NASICON‐related) 0.877 0.48 ІІІ 0.357 ІV 1.643 (langbeinite‐related) have been established. new obtained compounds were using FTIR‐spectroscopy, powder single crystal X‐ray diffraction optical microscopy methods. influence alkaline metal...