Boris Makeev

Boris Makeev
Komi Scientific Center · Институт геологии

About

110
Publications
6,530
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387
Citations
Citations since 2016
91 Research Items
379 Citations
2016201720182019202020212022020406080100
2016201720182019202020212022020406080100
2016201720182019202020212022020406080100
2016201720182019202020212022020406080100
Additional affiliations
December 1994 - present
Russian Academy of Sciences
Position
  • Komisc

Publications

Publications (110)
Article
Показана возможность твердофазного синтеза мультикомпонентных танталатов и ниобатов висмута со структурой пирохлора (пр. гр. Fd-3m), содержащих в эквимолярных количествах атомы переходных 3d-элементов. Состав таких пирохлоров может быть описан стехиометрической формулой Bi2Cr1/6Mn1/6Fe1/6Co1/6Ni1/6Cu1/6Ta(Nb)2O9 ± ?. Особенностью синтеза пирохлоров...
Article
X-ray spectroscopy methods (XPS, NEXAFS) were used to study the electronic state of the ions that make up pyrochlores (sp. gr. Fd-3m, No. 227) Bi2Mg1-xMxTa2O9+Δ (M-Cr,Mn,Fe,Co,Ni,Cu). It has been established that doping of bismuth magnesium tantalate pyrochlore with 3d-ions does not affect the electronic state of bismuth and magnesium ions, which a...
Article
New pyrochlores (sp. gr. Fd-3m) of Bi2Mg(Zn)1-хMхTa2O9.5-Δ (M-Cr, Fe) composition were obtained for the first time by the method of solid-phase synthesis. The process of phase formation of pyrochlores in the temperature range 650–1050 ºС was studied. It has been established that the precursor of the pyrochlore phase in all cases is orthorhombic bis...
Article
The Bi1.6Сr0.8Ta1.6O7±Δ pyrochlore was synthesized by the solid-phase method (sp. gr. Fd-3m:2, 10.45523(3) Å, Z=8). The thermal stability of the pyrochlore in air up to 1140°C has been established. With increasing temperature (30–1200°C), the unit cell parameter and the thermal expansion coefficient uniformly weakly isotropically increase from 10.4...
Article
A family of high-entropy solid solutions based on bismuth tantalate with a pyrochlore structure (sp. gr. Fd-3m) containing transition 3d-element atoms in equimolar quantities was obtained for the first time by the method of solid-phase synthesis. The composition of pyrochlores can be described by the stoichiometric formulas Bi2A1/6B1/6C1/6D1/6E1/6F...
Article
The phase formation process of Bi2FeTa2O9.5 (sp. gr. Fd-3m) synthesized by traditional ceramic technology was studied. Bismuth orthotantalate BiTaO4 (sp. gr. Pnna) was found to be the precursor of the pyrochlore phase. The high-temperature synthesis of the iron-containing pyrochlore and the formation of a characteristic dendrite-like microstructure...
Article
Nickel pyrochlore with the composition Bi2NiTa2O9 (sp. gr. Fd-3m, a = 10.5238 Å) was synthesized by the solid-phase reaction method. The phase formation process for nickel-containing bismuth tantalate Bi2NiTa2O9 with pyrochlore structure was investigated. The synthesis reaction for the pyrochlore phase is described by the interaction of orthorhombi...
Article
Методом твердофазной реакции синтезирован никелевый пирохлор состава Bi2NiTa2O9 (пр. гр. Fd-3m, a = 10,5238 ?). Исследован процесс фазообразования никельсодержащего танталата висмута Bi2NiTa2O9 со структурой пирохлора. Реакция синтеза фазы пирохлора описывается взаимодействием ортотанталата висмута ромбической модификации и оксида никеля. Синтез пр...
Article
Full-text available
Our multidisciplinary petrologic, mineralogical, and geochemical studies of volcanic material sampled from three chronologically discrete, but successive, ash discharges during the period from November 30, 2020 to January 18, 2021 were concerned with grain-size inhomogeneity, chemical and mineral phase composition, the concentrations of trace eleme...
Article
The pyrochlore with the composition Bi2FeTa2O9.5 was obtained by solid-phase synthesis. The electronic state and the nature of the local environment of iron atoms were studied by electron spin resonance (ESR) and Mössbauer spectroscopy. In the Bi2FeTa2O9.5 ESR spectra a dipolar-broadened line with g ∼ 2.05 from Fe3+ ion clusters are observed. This...
Article
The new pyrochlore with the composition Bi1.6Co0.8Ta1.6O7±Δ (sp. gr. Fd-3m:2, 10.5526(2) Å, Z = 8 (No. 227)) was obtained by the method of solid-phase synthesis. The sample is characterized by a dense microstructure with a small number of pores formed by partially fused grains. The electronic states of the atoms were studied by the near edge X-ray...
Article
Potassium feldspar (Kfeldspar), along with albite, is one of the leading minerals of alkaline ore (rare-metal-rare-earth) fenites of the Kosyu ore cluster of the Middle Timan. In the studied potassium feldspars, the data on an insignificant admixture of sodium oxide (0.19-0.38 wt.%) according to the results of microprobe analysis are confirmed by X...
Article
Full-text available
The solid-phase ceramic method was used to synthesize cobalt-containing solid solutions based on SrBi2Nb2O9. NEXAFS (Near Edge X-ray Absorption Fine Structure) and FTIR spectroscopy were used to study the electronic state of cobalt atoms in solid cross-links with a layered perovskite-like structure. It was found that cobalt atoms are in high-spin s...
Article
Full-text available
Calcium-copper titanate has been thoroughly studied by scientists around the world for several decades due to the manifestation of colossal dielectric permeability values (ε ~104 –105) in wide frequency ranges (102 –106 Hz) and temperature ranges (100 – 600 K), showing neither ferroelectric nor relaxor properties. Due to the unique dielectric chara...
Article
Full-text available
The samples of Ni-doped bismuth magnesium tantalate pyrochlores with the general formula Bi1.4(Mg1-xNix)0.7Ta1.4O6.3 (x = 0.3, 0.5, 0.7) were obtained by solid-phase synthesis. The crystal structure of pyrochlore type (sp. gr. Fd-3m:2) was clarified by the Rietveld method on the basis of X-ray powder diffraction (XRD) data. The unit cell parameters...
Article
Full-text available
Research subject . The Savabeisky sulfide copper-nickel ore occurrence, located in the central part of the Khengur (Central Pay-Khoy) gabbro-dolerite complex of the Pay-Khoy, within the Yugorsky Peninsula, located in the Far North-East of the European part of Russia, in the Arkhangelsk region, between the Barents and Kara Seas. Materials and method...
Article
Full-text available
The results of the study of accessory chrome spinels from heavy mineral concentrates of gold-bearing psephites of the Kyvvozhsky gold-placer field (Volsko-Vymskaya ridge, Middle Timan) are presented. As a result of the study of the typochemistry of chromspinelides, their genetic relationship with rocks of mainly alkaline-ultrabasic composition — an...
Article
Full-text available
This paper reports the first multidisciplinary petrologic, mineralogical, and geochemical studies of the near-crater tephra discharged by the 1669 catastrophic eruption of Etna stratovolcano, Sicily. We studied the grain-size distribution, chemical and mineral-phase composition of the tephra. We determined the composition of trace elements and the...
Article
Full-text available
The research was conducted in the European northeast of Russia (Komi Republic), in the reclaimed quarries for mining construction sand in the middle taiga subzone, in the course of two decades after the forest reclamation (Pinus sylvestris) had been applied. The specific features of initial pedogenesis on substrates of different textures have been...
Article
The solid solutions based on the pyrochlore-type system Bi2MgNb2-xTaxO9 were formed in the compositional range х = 0 – 2.0 (Bi1.6Mg0.8Nb1.6-tTatO7.2, t=0-1.6). The Rietveld method was used to refine the structure for Bi2MgNb2-xTaxO9 (x = 0, 1.0, 2.0). The increasing tantalum content led to the slight decrease in the cubic unit cell parameters from...
Conference Paper
The results of electron microscopic, X-ray, IR-spectroscopic and X-ray microprobe studies of atacamite mineralization of fumarole origin on Alaid volcano (Kuril island arc) are discussed.
Article
Full-text available
We studied Upper Paleozoic (P1pt-ng) carbonaceous shales and siltstones from the area of the Ust'-Kara astrobleme (PayKhoy). We analyzed mineralogical and geochemical features of carbonaceous rocks of the target in the vicinity of the Ust'-Kara astrobleme event using a complex of modern methods to identify possible mobilization, redeposition and co...
Article
Mn-doped CCTO samples were synthesized using standard ceramic technology. Two series of samples of the composition CaCu3Ti4-4xMn4xO12-δ and CaCu3-3xMn3xTi4O12+δ (0.005≤х≤0.06) have been investigated. According to XRD data, the samples contain copper oxide (less than 1 mol %), the largest amount of which is in CaCu3Ti4-4xMn4xO12-δ. According to XPS...
Article
Full-text available
Two series of iron-containing solid solutions Bi2Mg1-xFexNb2O9+δ and Bi2MgNb2-2xFe2xO9-δof pyrochlore structure were obtained by the traditional solid phase synthesis method. The electronic state and character of exchange interactions of iron atoms in solid solutions were investigated by methods of magnetic dilution and NEXAFS-spectroscopy. Accordi...
Article
Two series of Bi2Mg1-xCoxNb2O9 and Bi2MgNb2-2xCo2xO9-δ preparations with pyrochlore structure were synthesized using solid phase method. It was found that solid solutions are formed in Bi2MgNb2-2xCo2xO9-δ series, foreign phases of MgNb2O6 and Bi5Nb3O15 are fixed in Bi2Mg1-xCoxNb2O9 samples, no impurity cobalt-containing phases were detected. The me...
Article
Full-text available
The electronic state and character of exchange interactions of nickel and chromium atoms in solid solutions of Bi5Nb3-3xМ3xO15-δ (М-Cr,Ni) was researched by methods of magnetic susceptibility and NEXAFS-spectroscopy. NEXAFS spectra of nickel and chromium oxides were obtained. According to X-ray spectroscopy in solid solutions, chromium atoms are ma...
Article
Full-text available
The results of mineralogical study of pyropes and olivine from the Vymskaya horst-anticline structure (Kyvvozh goldbearing placer field, Middle Timan), that found during the heavy mineral concentrate sampling, are presented. Optical microscopy, electron microprobe, and scanning electron microscope were used in the research. High preservation of the...
Article
The methods of magnetic dilution, thermal analysis, ESR (Electron Spin Resonance), Mössbauer and NEXAFS (Near-Edge X-ray Absorption Fine Structure) spectroscopy were used to study iron-doped solid solutions of calcium copper titanate CaCu3Ti4-4xFe4xO12-δ (0.005 ≤ x ≤ 0.08, 0.2) and CaCu3-3xFe3xTi4O12+δ (0.005 ≤ x ≤ 0.06) synthesized by the standard...
Article
The microstructure and phase transformations of copper atom doped ceramic BiNbO4 synthesized at 950 and 1100°C were studied. According to XPA the samples in compact, pressed form crystallize in the α-BiNbO4 structure irrespective of the synthesis temperature and in spite of the phase transformation α → β at 1040°C. The substances BiNb1–xO4–δ∙xCuO (...
Article
Full-text available
Multidisciplinary petrologic, mineralogical, and geochemical studies have been carried out for the first time concerning near-crater tephra from the world-largest intraplate stratovolcano (Erebus). The volcano is characterized by a unique basanite-phonolite effusive lineage. We studied the grain-size and chemical compositions of the tephra and the...
Article
Full-text available
The methods of NEXAFS, EPR spectroscopy and static magnetic susceptibility were used to analyze the condition and nature of exchange interaction of paramagnetic cobalt atoms within the bismuth niobate Bi3NbO7 matrix. The samples of Bi3Nb1-xCoxO7-δ with cubic fluorite-like structure were synthesized by the solid-phase method; their microstructure an...
Article
Two series of Ni-doped CaCu3Ti4O12 ceramics with CaCu3Ti4-4хNi4хO12-δ and CaCu3-3хNi3хTi4O12 compositions were obtained by the solid-phase synthesis method. The magnetic behavior of the samples in the range of 77–400 K was studied by magnetic dilution. For the first time the samples of both series were characterized by the spectroscopic methods: XP...
Article
Thermal and electrical properties of copper oxide doped BiNbO4 ceramics as well as its spectral characteristics and microstructure were studied in this work. According to XRD, the samples calcined at 950 °C and 1100 °C had the structure of α-BiNbO4 in spite of the phase transition α→γ(β) at 1040 °C. The studied composite samples had the composition...
Article
ESR, XPS and NEXAFS spectra, as well as magnetic and electric properties of CaCu3Ti4O12 synthesized by the solid-phase method within 6,12,24,48 and 60 h were studied. The analysis of magnetic susceptibility of CaCu3Ti4O12 and magnesium-containing solid solutions of CaCu3-3xMg3xTi4O12 revealed antiferromagnetic exchange interactions between Cu param...
Article
Full-text available
The electron state and the nature of the exchange interactions of cobalt atoms in BiNb1-xСoxO4-δ solid solutions of triclinic and orthorhombic modifications were studied using the magnetic susceptibility and NEXAFS-spectroscopy. In order to determine the electronic state of cobalt atoms, the solid solutions and oxides of cobalt CoO, Co3O4 were stud...
Article
Full-text available
UHPHT natural glasses are interesting not only to geologists and mineralogists, but also to physicists, chemists, and materials scientists from the point of view of the fundamental problem of the existence of matter under extreme PT-conditions. The specificity of the structure of such materials requires complex study. In this work we used optical,...
Article
Full-text available
In order to study the electronic state of Fe atoms and interatomic exchange interactions in solid solutions of Bi2CaNb2−2xFe2xO9−δ with perovskite structure, methods of magnetic dilution, NEXAFS, XPS and EPR spectroscopy were used. Increased values of the magnetic moment of iron atoms in solid solutions compared to pure spin values for Fe(III) are...
Article
Full-text available
The samples of solid solutions of Bi₂BaNb₂₋₂ₓСo₂ₓO₉₋δ composition at x 0:04 were synthesized by the solid-phase method. The electron state and the nature of the exchange interactions of cobalt atoms in the samples were studied by the measurements of magnetic susceptibility and NEXAFS-spectroscopy. The NEXAFS spectra of the solid solutions and the c...
Article
sp 2 Amorphous carbons are considered as objects of the modern nanotechnology. A particular set of the highest carbon content sp 2 species, two natural amorphous carbons (shungite carbon and antraxolite) as well as two engineered carbon blacks were subjected to analytical study by using a set of selected modern structural and compositional analytic...
Article
Results of geochemical studies of suevites of the Kara astrobleme (Pay-Khoy) produced by a new approach based on square microprobe analysis of suevite matrix and consolidated impact melts with multivariate statistics have been described for the first time. At list three suevite varieties have been divided which are essentially differ by geomorpholo...
Article
Full-text available
The results of geochemical studies of the diamondiferous suevites of the Kara astrobleme (Pay-Khoy) using a new approach based on “area” microprobe analysis of suevite matrix and consolidated impact melt aggregates with subsequent data processing by multivariate statistic methods are described for the first time. At least three suevite varieties th...
Preprint
Full-text available
The suggested approach "Selected set of samples + selected set of analytical tools" occurred quite efficient when applying to sp 2 amorphous carbons, thus providing a transformation of 'amorphous' representation of the issue, based on particulars, into a 'crystalline' one based on a limited set of fixed commonalities. The slogan first part implies...
Article
Phase transformations of bismuth orthoniobate BiNbO 4 were studied by the methods of differential scanning calorimetry and high-temperature X-ray diffraction. The DSC curve in the heating–cooling mode of the orthorhombic samples (α-BiNbO 4 ) showed endothermic and exothermic effects associated with the phase transition from the orthorhombic modific...
Preprint
Full-text available
The approach based on selected set of samples and selected set of analytical tools occurred quite efficient when applying to amorphous carbons thus leading to a transformation of the current representation of the issue based on particulars into that one based on a limited set of fixed commonalities. The approach first part implies a set of differen...
Preprint
Full-text available
The approach based on selected set of samples and selected set of analytical tools occurred quite efficient when applying to amorphous carbons thus leading to a transformation of the current representation of the issue based on particulars into that one based on a limited set of fixed commonalities. The approach first part implies a set of differen...
Article
Thermal behavior of the orthorhombic (α) and triclinic (β) polymorphs of BiNbO4 was studied by the methods of high-temperature powder X-ray diffraction (HTPXRD) and differential scanning calorimetry (DCS) in the temperature range 25-1200 °C. The study revealed the sequence of thermal phase transformations and the new high-temperature modification,...
Article
Full-text available
The manganese-doped polymorphs of bismuth orthoniobate were studied using thermal analysis, ESR, XPS and NEXAFS spectroscopy. It was shown that the phase transition from the orthorhombic ( α ) to the triclinic ( β ) modification can be reversible and it can be achieved by prolonged calcination of samples at 750°C. The DSC curves revealed no thermal...
Article
Full-text available
The majority of bismuth-containing compounds with a layered perovskite-like structure, analogues of the so-called Aurivillius phases, are of practical and theoretical interest owing to their ferroelectric properties. Bismuth niobate Bi 5 Nb 3 O 15 belongs to the group of mixed layered compounds. Its structure is characterized by the ordered alterna...
Article
Unusual carbonaceous matter, termed here chiemite, composed of more than 90% C from the Alpine Foreland at Lake Chiemsee in Bavaria, southeastern Germany has been investigated using optical and atomic force microscopy, X‐ray fluorescence spectroscopy, scanning and transmission electron microscopy, high‐resolution Raman spectroscopy, X‐ray diffracti...
Article
Unusual carbonaceous matter, termed here chiemite, composed of more than 90% C from the Alpine Foreland at Lake Chiemsee in Bavaria, southeastern Germany has been investigated using optical and atomic force microscopy, X‐ray fluorescence spectroscopy, scanning and transmission electron microscopy, high‐resolution Raman spectroscopy, X‐ray diffracti...
Article
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Приведены результаты сравнительных минералого-геохимических исследований материала пеплов вулканов Ключевского и Камбального, практически одновре- менно извергавшихся на Камчатке в марте–апреле 2017 г. Определены химиче- ский, фазовый, нормативно-минеральный и микроэлементный составы вещества. Проанализирован состав водных вытяжек из пеплов. По ком...
Article
Phase transformations and thermal stability of nickel-containing solid solutions of bismuth orthoniobate BiNbO4 were studied by methods of thermal and X-ray phase analysis. The DSC curve of the BiNb1-xNixO4-δ samples exhibited endothermic effects near the temperatures of 1049 °C and 1227 °C during the heating, and exothermic effects at ˜990 °C duri...
Article
Thermal stability, magnetic properties, ESR (Electron Spin Resonance) and NEXAFS (Near-Edge X-ray Absorption Fine Structure) spectra of the orthorhombic and triclinic modifications of solid solutions BiNb1-xMnxO4-δ have been studied. X-ray diffraction determined the reversibility of the phase transition from the high-temperature triclinic modificat...
Article
The methods of EPR and NEXAFS spectroscopy were employed for the study of BiNb1-xFexO4-δ solid solutions of triclinic and orthorhombic modifications. The analysis of the NEXAFS Fe2p-spectra of iron oxides and the iron-containing solid solutions revealed that Fe atoms were mainly in an oxidation state of +3. In the EPR spectra of the BiNb1-xFexO4-δ...
Article
The results of studying the structural and chemical transformations of natural bitumens of different degrees of metamorphism under heating at a low vacuum (∼8 kPa) in the temperature range 400–1000 °C are presented. Reducing of the size of supermolecular particles during heating was recorded. A sequent step-by-step transformation of the graphite-li...
Article
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EPR of solid solutions BiNb1−xMnxO4−δ in triclinic modification have been studied. The EPR spectra revealed sextet structure of Mn(II) ions with 8.4 mT splitting and some features at g = 3.80 and 1.47, and a broad diffuse band with g ≈ 2.2 having a sextet with 8 ÷ 9 mT splitting and g = 2.0 against its background. The modeling has shown that the be...