Victor Verbetsky - Academia.edu (original) (raw)

Papers by Victor Verbetsky

Key Engineering Materials, 2022

Nitrides of ‘2:17’ - type based on rare earth metals and iron are of interest as promising magnet... more Nitrides of ‘2:17’ - type based on rare earth metals and iron are of interest as promising magnetic materials for the development of high-energy permanent magnets. The magnetic properties and phase composition of the starting compound Sm1.8Er0.2Fe17, nitride Sm1.8Er0.2Fe17N2.1 and its crushed powders have been investigated. The magnetic measurements of the samples were studied in magnetic fields up to 70 kOe at room temperature. It was found that the introduction of nitrogen atoms into the crystal lattice of the substituted composition (Sm,Er)2Fe17 in combination with the effect of high-energy milling of nitride leads to an increase in the saturation magnetization (σS) and coercive force (HC).

Zavodskaya Laboratoriya. Diagnostika Materialov, 2017

Participation of iron and titanium valence states in covalent and ionic components of metal-hydro... more Participation of iron and titanium valence states in covalent and ionic components of metal-hydrogen bonding in FeTiH x hydrides has bee11 investigated by means of X-ray emission spectroscopy. Both iron and titanium valence p-states take an active part in the formation of hybrid sub band. At the same time X-ray emission spectra didn't show any significant pal.ticipation of iron d states in metalhydrogen bonding. Correlation between the electronic structure and technologically applicable properties of FeTiHx hydrides has been established.

Energies, 2020

The hybrid hydrogen storage method consists of the combination of both solid-state metal hydrides... more The hybrid hydrogen storage method consists of the combination of both solid-state metal hydrides and gas hydrogen storage. This method is regarded as a promising trade-off solution between the already developed high-pressure storage reservoir, utilized in the automobile industry, and solid-state storage through the formation of metal hydrides. Therefore, it is possible to lower the hydrogen pressure and to increase the hydrogen volumetric density. In this work, we design a non-stoichiometric AB2 C14-Laves alloy composed of (Ti0.9Zr0.1)1.25Cr0.85Mn1.1Mo0.05. This alloy is synthesized by arc-melting, and the thermodynamic and kinetic behaviors are evaluated in a high-pressure Sieverts apparatus. Proper thermodynamic parameters are obtained in the range of temperature and pressure from 3 to 85 °C and from 15 to 500 bar: ΔHabs. = 22 ± 1 kJ/mol H2, ΔSabs. = 107 ± 2 J/K mol H2, and ΔHdes. = 24 ± 1 kJ/mol H2, ΔSdes. = 110 ± 3 J/K mol H2. The addition of 10 wt.% of expanded natural graphit...

ChemEngineering, 2018

Hydrogen interactions with Nd 2 Fe 17 and Nd 2 Fe 14 B was investigated by means of the calorimet... more Hydrogen interactions with Nd 2 Fe 17 and Nd 2 Fe 14 B was investigated by means of the calorimetric method with application of differential heat-conducting calorimeters that were of the Tean-Calvet type. The reaction of hydrogen absorption and desorption was carried out at 250 and 300 • C for Nd 2 Fe 17 , while the pressure-composition-isotherms (P-C-T) and enthalpy change with hydrogen concentration in the intermetallic compound (IMC) were obtained. The Nd 2 Fe 14 B-H 2 system was studied at 50 • C and the dependence of the enthalpy change with hydrogen concentration in the intermetallic compound was also obtained. Based on the measured data, the assumption about the order of filling the interstitial sites by hydrogen atoms was made.

Solid State Phenomena, 2016

The hydrogenation of TbNi0.4Co0.6 was studied by means of neutron diffraction and calorimetric me... more The hydrogenation of TbNi0.4Co0.6 was studied by means of neutron diffraction and calorimetric method with use of the differential heat-conducting Tian-Calvet type calorimeter. It was determined that TbNi0.4Co0.6H3.8 crystallized in orthorhombic CrB-type structure (S.G. Cmcm). The hydride formation is accompanied with strong lattice expansion. In the structure TbNi0.4Co0.6D3.4 deuterium atoms occupy tetrahedral 8f-intersices, trigonal bipyramidal 4c-interstices and octahedral 4b-interstices. Dependence of the differential molar enthalpy of absorption (ΔHabs) vs. the hydrogen concentration in the metallic matrix was obtained at 50°C. It was ascertained that in the range of 0

The binary systems R3Ni exhibit several anomalius in the electrical, magnetic and structural prop... more The binary systems R3Ni exhibit several anomalius in the electrical, magnetic and structural properties [1,2]. In this connection peculiarities of interaction of R3Me compounds with hydrogen and nitrogen, in particular the problem of thermal stability of formed hydrides and nitrides was investigated in the temperature range 293-243 K.

Solid State Communications, 1990

Participation of d and p symmetry valence electrons of iron and cobalt in metal-hydrogen bonding ... more Participation of d and p symmetry valence electrons of iron and cobalt in metal-hydrogen bonding in the Mg2FeH6 and Mg2CoH5 hydrides has been investigated on the basis of X-ray emission spectroscopy data. An additional charge acquired by iron and cobalt atoms in the hydrides has been measured and the role played by hydrogen atoms as a binding component in the investigated hydrides has been explained.

Inorganic Materials, 2007

We describe the synthesis of CeNi 3 D x deuterides at normal and high deuterium pressures. X-ray ... more We describe the synthesis of CeNi 3 D x deuterides at normal and high deuterium pressures. X-ray and neutron diffraction techniques were used to identify the position and determine the positional parameters of the metal and deuterium atoms. The deuterides are isostructural with the parent compound CeNi 3 but have a larger unit cell. Increasing the deuterium content to the composition CeNi 3 D 5.2 leads to partial amorphization of the material. The variation in unit-cell volume observed at low and high deuterium contents indicates that the metal-deuterium bonds are partially ionic and partially metallic.

ChemInform, 2010

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was e... more ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Journal of Thermal Analysis and Calorimetry, 2014

The present work deals with the study of the reaction of hydrogen desorption from the CaSiH X hyd... more The present work deals with the study of the reaction of hydrogen desorption from the CaSiH X hydride by means of the calorimetric method. The dehydrogenation of the CaSiH X hydride was carried out at 548 K. For a calorimetric study, the installation composed of the differential heat-conducting Tian-Calvet type calorimeter connected with a conventional Sieverts-type apparatus was employed. Such installation permitted us to obtain simultaneously the P-X isotherms (P-equilibrium hydrogen pressure, X = H/ CaSi) and variation of the partial molar enthalpies of the reaction of hydrogen desorption from CaSiH X with the hydrogen concentration in the metallic matrix. It was ascertained that in the CaSi-H 2 system there was one region where values of the partial molar enthalpy of the reaction of hydrogen desorption from the CaSiH X hydride remained constant. This means that formation of one hydride phase in the CaSi-H 2 system took place. The enthalpy and entropy values for the reaction of hydrogen desorption from the CaSiH X in the plateau range are DH des = 53.8 ± 1.2-kJ mol-1 H 2 and DS des = 94.2 ± 2.7 J mol-1 H 2 K-1 (DH des and DS des-the differential molar enthalpy and entropy desorption, respectively).

Inorganic Materials: Applied Research, 2014

We have studied the interaction of hydrogen with V-Mo and V-Mo-Ti alloys. Hydrogen absorp tion an... more We have studied the interaction of hydrogen with V-Mo and V-Mo-Ti alloys. Hydrogen absorp tion and desorption isotherms have been measured, the stability ranges of the forming hydride phases have been determined, and the ΔH and ΔS of the reactions involved have been calculated. X ray diffraction results indicate the formation of three hydride phases, with FCC and BCC structures.

Journal of Solid State Electrochemistry, 2003

The effect of the stoichiometric factor on the electrochemical and gas-phase behavior of hydridef... more The effect of the stoichiometric factor on the electrochemical and gas-phase behavior of hydrideforming intermetallic alloys of the Ti 0.45 Zr 0.55 Ni y-V 0.45 Mn x general composition is studied. The structure and the phase composition of the alloys were investigated by means of X-ray diffraction, electron microscopy, and electron probe microanalysis. An introduction of hydrogen does not change the structure type and hydriding is accompanied by an isotropic increase in the cell volume by about 20%. The alloys studied demonstrate maximum values of hydrogen sorption capacity, discharge capacity, and good rate capability throughout a wide range of compositions, rather than in a narrow region in the vicinity of the stoichiometric composition. Keywords MH electrodes AE Intermetallic compounds (IMC) AE Crystal structure AE Hydrogen absorption AE Discharge capacity

Journal of Magnetism and Magnetic Materials, 2003

The structural and magnetic characterization of Ho2Fe17Hx (x=0,3) single crystals is presented. T... more The structural and magnetic characterization of Ho2Fe17Hx (x=0,3) single crystals is presented. The host alloys crystallises with a disordered variant of hexagonal (Th2Ni17-type P63/mmc) structure. The host alloys symmetry is retained upon hydrogenation. A significant change of the magnetization process after hydrogenation has been observed in hydride Ho2Fe17H3. Hydrogenation induces transition FOMP-type in the Ho2Fe17H3 compound.

Journal of Alloys and Compounds, 1999

Synthesis of LaCo H was performed under a 10-bar pressure of hydrogen and at the temperature of 6... more Synthesis of LaCo H was performed under a 10-bar pressure of hydrogen and at the temperature of 600 K. Nitriding was carried out 13 3.5 in a nitrogen atmosphere of 30 bar pressure and at temperature 700 K. The structure of LaCo N was refined by the full-profile analysis 13 3 using the GSAS program. Magnetic measurements were made on free and aligned samples in the temperature range 78-750 K and magnetic fields up to 13 kOe with a pendulum magnetometer. The saturation magnetisations s of LaCo hydride and nitride were s 1 3 measured on fine powder samples at temperatures of 300 and 78 K. The data obtained indicate insignificant change of the hydride saturation magnetisation in comparison with initial sample, while the saturation magnetization of nitride decreases by 26.5%. Values of the anisotropy fields of these compounds, as well as their saturation magnetisation values, show insignificant changes at the room temperature and 78 K, which are the characteristics of compounds with high Curie temperatures. However, hydriding and nitriding lead to a rise in the peculiarities in the behaviour of s(T) at temperature T5480 K, namely, an increase of magnetization in the hydride LaCo H and a 13 3.5

Journal of Alloys and Compounds, 2011

The paper reports the influence of hydrogen absorption on the structure and magnetic properties o... more The paper reports the influence of hydrogen absorption on the structure and magnetic properties of intermetallic compounds RNi (R = Gd, Tb, Dy, Sm) and R 6 M 1.67 Si 3 (R = Ce, Gd, Tb; M = Ni, Co). It is demonstrated that the ternary hydrides GdNiH 3.2 , TbNiH 3.4 , DyNiH 3.4 , and SmNiH 3.7 have similar CrB-type orthorhombic structures. In the structures of TbNiD 3.4 and DyNiD 3.4 , deuterium atoms occupy tetrahedral 8f-interstices [R 3 Ni], trigonal bipyramidal 4c-interstices [R 3 Ni 2 ], and octahedral 4b-interstices [R 4 Ni 2 ]. The hydrides of R 6 M 1.67 Si 3 retain the hexagonal structure of their parent compound. In the structures of Tb 6 Co 1.

Journal of Alloys and Compounds, 1997

Magnetocrystalline anisotropy of Y2Fel7 and of its nitride and hydrides has been measured on magn... more Magnetocrystalline anisotropy of Y2Fel7 and of its nitride and hydrides has been measured on magnetically oriented samples. The anisotropy is defined by the local site anisotropy behavior and in a first approximation depends mainly on the lattice expansion along the c axis.

Journal of Alloys and Compounds, 2003

The structure of several Laves phase alloys and deuteride was studied using methods of X-ray anal... more The structure of several Laves phase alloys and deuteride was studied using methods of X-ray analysis and time-of-flight neutron diffraction. The refinement of diffraction profiles was performed using the Rietveld method. Introduction of hydrogen does not change the metal matrix structure and the hydriding is accompanied by isotropic increase of cell volume by 20%. The minimisation of the R-factor showed that the best fit is achieved for the model of deuterium location in three sites, 24(l), 12(k) and 6(h). However, at low temperature 1 1 approximately 0.11 deuterium atoms relocate from the 24(l) to the 12(k) position. The analysis of alloy and deuteride structure performed 1 in this work as well as the reference data allow to draw a conclusion, that the set of sites in hexagonal Laves phase structure which are occupied by deuterium is a stable one and does not depend on temperature or alloy composition.