Alexander Nikolaevich Pirogov

Alexander Nikolaevich Pirogov
Ural Federal University | UrFU · Department of Physics

Seniour scientist, Institute of Metal Physics, UB RAS, Ekaterinburg

About

162
Publications
9,655
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
1,486
Citations
Citations since 2016
28 Research Items
475 Citations
20162017201820192020202120220204060
20162017201820192020202120220204060
20162017201820192020202120220204060
20162017201820192020202120220204060
Introduction
Additional affiliations
April 2013 - present
Ural Federal University
Position
  • Professor-researcher
Description
  • I study magnetic structures and magnetic properties on chair of Magnetism and magnetic nanomaterials
February 2013 - December 2017
Ural Federal University
Position
  • Professor-researcher

Publications

Publications (162)
Article
The neutron diffraction, magnetic and heat capacity measurements have been carried out to study the polycrystalline sample LiNi0.5Co0.5PO4prepared by the glycerol-nitrate synthesis method. Models of Ni- and Co-ion occupation the 4сoctahedral position in a crystal structure LiNi0.5Co0.5PO4are calculated for a paramagnetic state. The best model is th...
Article
Full-text available
The LiNiPO4 , LiNi0.9Mn0.1PO4 , and LiNi0.9Co0.1PO4 single crystals are studied with heat capacity and neutron diffraction measurements over the temperature interval (10–30) K. Two peaks are observed on the temperature dependence of heat capacity for LiNiPO4 , and LiNi0.9Co0.1PO4 samples. One peak indicates the first order phase transition from an...
Article
This study is devoted to magnetic neutron diffraction analysis (elastic neutron scattering yielding information about spin ordering in magnetic materials). Experimental approaches to magnetism are intensely developed mainly due to the discovery of new functional materials with unusual properties. Nevertheless, magnetic neutron diffraction analysis...
Article
Full-text available
Polycrystalline orthophosphates LiNi1−xCoxPO4 (x = 0, 0.1, 0.2, 0.3, 0.4, and 0.5) have been prepared by the glycerol-nitrate synthesis method and used to study by the scanning electron microscopy, X-ray fluorescence analysis, X-rays diffraction and Raman scattering. All the LiNi1−xCoxPO4 polycrystalline samples contain particles having average cry...
Conference Paper
Pressure leaching is one of the most high-demanded and promising hydrometallurgical technology, which allows one to obtain high efficiency. Taking into account the shutdown of zinc plant in Vladikavkaz («Electrozinc, Lls.») searching the modern methods of zinc production is of current interest. In this work, the issue was observed on influence of t...
Article
Full-text available
Spontaneous and magnetic field induced incommensurate – commensurate magnetic phase transitions have been studied in Tb 1- x Er x Ni 5 compounds near the critical concentration x c = 0.125. Compounds crystallize in the hexagonal CaCu 5 type phase (P6/mmm space group). In compounds with x ≥ x c the magnetic order is a commensurate ferromagnetic one....
Article
Full-text available
We present the magnetic properties of LiNi 1-x Co x PO 4 magnetoelectrics, with x = (0–0.2), and their analysis of concentration dependences. Samples have been synthesized by a glycerol-nitrate method. To refine crystal structure X-ray diffraction measurements were carried out. Magnetic measurements were performed at the external magnetic field of...
Article
Full-text available
Sr2Ni1–xMgxMoO6 (x = 0.25 and 0.5) double perovskites were synthesized by pyrolysis of glycerol–salt mixtures and their magnetic properties were investigated. X-ray diffraction was employed to refine crystal structures of these perovskite materials and set sample purity degree. The magnetic ground state of Sr2Ni1–xMgxMoO6 (x = 0.25 and 0.5) has bee...
Article
Physical quantities affecting the magnitude of magnetocaloric effect in ferro- and ferrimagnetic materials with first and second order magnetic phase transitions are considered. Governing equations for the main characteristics of the magnetocaloric effect are given and analyzed. Their outcomes are compared with the experimental results.
Article
Neutron irradiation allows the materials to transform to a state, in which the properties of material become different from an initial state. This paper presents the results of neutron irradiation of several magnetic materials including intermetallic compounds Nd2Fe14B and Er2Fe14B, multiferroics BiFe0.95Mn0.05O3 and Bi0.85La0.15FeO3, oxides LiMn2O...
Article
Full-text available
The magnetic structures that form in La1–xRx Mn2Si2 (R = Sm, Tb) layered compounds with various concentrations x have been determined by magnetic neutron diffraction and magnetic measurements, and the magnetic phase diagrams have been built. It is shown that the formation of the magnetic structures is dependent not only on exchange interactions, bu...
Article
Elastic modulus and hardness, X-ray and neutron diffraction, small-angle scattering and neutron tomography have been used to study bone samples of healthy people and those suffering from osteoporosis. The samples under studied belonged to people of different ages: a child, middle and elderly. The crystalline structure of the mineral part of the bon...
Article
The magnetic structure of La1-xTbxMn2Si2 compounds with 0 ≤ x ≤ 1 has been studied by powder neutron diffraction and magnetization measurements on single-crystal samples. We demonstrate that at 4.2 K, with increasing the Tb concentration, a canted ferromagnetic structure of LaMn2Si2 changes at x > 0.2 to a canted antiferromagnetic structure. The an...
Article
Full-text available
The sorption of acetone from the vapor phase by Keplerate polyoxomolybdate (POM) nanoclusters, Mo132 and Mo72Fe30, and Mo138, a POM with a toroid structure, is studied via equilibrium interval sorption (a modification of vapor sorption gravimetry). The highest sorption capacity is registered for Mo132, while the other two show performance an order...
Article
Full-text available
We present susceptibility, X-ray and neutron diffraction data on powder orthophosphates LiMnPO4, LiFePO4, LiNi0.9Co0.1PO4, and LiNi0.9Mn0.1PO4. Dependences of structure parameters and magnetic state of these compounds on type of 3d element and content of 3d-electrons have been studied. Magnetic moment of 3d-transition ion is orientated along a-axis...
Article
Full-text available
p>We studied crystal and magnetic structures of some composite and single-phase multiferroics: ( x )MFe<sub>2</sub>O<sub>4</sub> + (1- x )BaTiO<sub>3</sub>, Ni<sub>3- y </sub>Co <sub>y</sub> V<sub>2</sub>O<sub>8</sub>, and Bi<sub>0.9</sub>Ba<sub>0.1</sub>Fe<sub>0.9</sub>Ti<sub>0.1</sub>O<sub>3</sub>. Composite multiferroics ( x )MFe<sub>2</sub>O<su...
Article
The Y1-xTbxMn6Sn6 compounds (x = 0, 0.175, 0.2, 0.225, 0.25) were studied by small angle neutron scattering (SANS) and paramagnetic neutron spin echo. The YMn6Sn6 compound is found to be a helimagnet in the whole temperature range below TN=310 K. Close to TN an additional peak of a Lorenz shape was observed at Q=0. The peak is thought to have origi...
Conference Paper
Magnetic properties of the lithium-transition metal orthophosphates LiNiPO4, LiNi0.9Co0.1PO4, LiNi0.9Mn0.1PO4 and LiMnPO4 single crystals have been studied. Temperature behavior of a susceptibility against a type of 3d-transition ion was analyzed. Anomalous behavior is observed over narrow temperature region near Neel point. This is caused by a com...
Conference Paper
Full-text available
Neutron diffraction has been carried out to study temperature evolution of crystal and magnetic structure parameters of the multiferroic (0.9)BiFeO3 + (0.1)BaTiO3 over region (300 – 1000) K. Crystal structure is rhombohedral over whole temperature region and it is described by the R3c space group. The lattice parameters increase with temperature. T...
Article
Some comments on the review by Sim et al. [(2016). Acta Cryst. B72, 3-19] are given. The review is devoted to hexagonal multiferroics RMnO3, in which there are ferroelectric and magnetic orders. Strong interaction between these orders causes a series of interesting properties of multiferroics.Some comments on the review by Sim et al. [(2016). Acta...
Article
Full-text available
A study of crystal and magnetic structures, heat capacity, magnetic and magnetocaloric properties of Ho(Co1-х Feх)2 (with increasing x from 0 to 0. 2) intermetallic compounds has been undertaken. Phase composition was controlled by X-ray diffraction analysis. Neutron diffraction experiment was performed at temperatures of 78 and 293K. Magnetic prop...
Article
In order to develop the neutron absorbing and shield materials, a hot-rolled 0.02%-Gd duplex stainless steel was prepared with 55 vol. % of ferrite and 45 vol. % of austenite. The σ phase with an average grain size of 9–11 μm in austenitic (γ) grains tended to be elongated parallel to the rolling direction, with (100) poles concentrated towards the...
Article
Full-text available
Multiferroic composites of (x)NiFe 2 O 4 + (1-x)BaTiO 3 with x = 0.2, 0.3 and 0.4 and (x)CoFe 2 O 4 + (1-x)BaTiO 3 with x = 0.2, and 0.4 have been synthesized by mixing NiFe 2 O 4 (CoFe 2 O 4) spinel and BaTiO 3 piezoelectric. Distribution of Ni (Co) ions on 8a and 16d positions of spinel lattice (space group F d-3m) is determined by neutron powder...
Article
Full-text available
An 8ZrO2 · Al2O3 solid solution of zirconia and alumina is studied by X-ray and neutron diffraction, small-angle neutron scattering, and nitrogen sorption. The samples are synthesized by the sol-gel method and then subjected to heat treatment at temperatures T an of 450, 600, and 950°C for 6-8 h. The first two samples are identified as X-ray amorph...
Article
Full-text available
The magnetic structure of YMn6Sn6 helimagnet has been studied by small-angle neutron scattering in the temperature range from 25 to 360 K. Two peaks with centers at 1.7 and 0 nm−1 have been observed in the dependences of the intensity of neutron scattering on the momentum transfer. An increase in the temperature is accompanied by a decrease in the...
Article
Full-text available
To study the evolution of structural and magnetic states of irradiation-amorphized Er2Fe13.8B alloy during isothermal annealing at temperatures of 295-1025 K, magnetization measurements and neutron diffraction analysis have been performed. The annealing of the alloy leads to the crystallization of the Nd2Fe14B-type phase, the amount of which reache...
Article
Full-text available
Abstract—This paper presents the results of investigations of the structural state and magnetic properties of nanocrystalline cupric oxide samples with average particle sizes of approximately 40 and 13 nm, which were synthesized by the electric explosion and gas phase methods, respectively. The samples have been studied using X�ray diffraction, neu...
Article
TbNi2Si2-TbMn2Si2 solid solutions have been studied by neutron diffraction to reveal magnetic structures with wave vectors {k 8} = μ(b 1–b 2) + b 3/2 = 2π [(1–2μ)/2, (1 + 2μ)/2, 0]/a, {k 13} = b 3/2 = 2π(1/2, 1/2, 0)/a, and {k 14} = 0. The method of calculation is described and the results of calculations are given for the basis functions of irredu...
Article
Full-text available
Neutron diffraction measurements of the Nd5Ge3 intermetallic compound with a hexagonal structure (space group P 63/mcm ) have been performed at temperatures of ~10 and 293 K. The basis functions of irreducible representations of the space group (P 63/mcm ), which are calculated as a result of the sym� metry analysis of possible magnetic structures...
Article
Magnetic susceptibility, magnetization and neutron diffraction measurements have been performed to study structure and magnetic states of crystalline and amorphous Nd2Fe14B and Er2Fe14B alloys. In the crystalline state there exists a large (about 20%) anisotropy of Er-sublattice magnetization. Values of the magnetic anisotropy constant of Er ions a...
Article
Full-text available
The magnetic properties of a mixed inter-metallic compound, Tb0.95Er0.05Ni5, were investigated using a neutron diffraction method at low temperatures. These compounds were known to have a successive magnetic phase transition from the paramagnetic state at high temperature to a lock-in phase at low temperature through intermediate phases, i.e., PM(p...
Article
Full-text available
The magnetic state of Y1 − x Tbx Mn6Sn6 (with x ≤ 0.25) alloy is studied at different temperatures and magnetic fields by neutron diffraction. The alloy with x c = 0.22 exhibits an incommensurate-to-commensurate structure phase transition. The transition is accompanied by a decrease in the unit-cell volume. The weak dependence of the intensity of s...
Article
Neutron diffraction experiments have been carried out to study the magnetocrystalline anisotropy of two (2b and 2d) Tm sublattices and four (4f, 6g, 12j, and 12k) Fe sublattices in ferrimagnetic compound Tm{sub 2}Fe{sub 17} (space group P6{sub 3}/mmc). We have determined the temperature dependence of the magnitude and orientation of magnetization f...
Article
The TbNi5 compound shows an interesting magnetic phase transition with an incommensurate structure below 23 K, whose true nature remains unresolved. In order to solve this question, we have carried out polarized neutron diffraction experiments by measuring temperature and field dependence of the intensities of satellites and Bragg reflections. From...
Article
The crystal structure and magnetic properties of ErFe2D3.1 have been studied by means of magnetic measurements and neutron powder diffraction in a wide temperature range from the highest temperature T = 450 K down to the lowest one T = 12 K. The crystal structure of ErFe2D3.1 is found to be strongly modified by temperature: the high-temperature cub...
Article
Full-text available
Rapidly quenched (RQ) alloys R 12Fe82B6 (R = Nd, Er) have been prepared by melt spinning. Their magnetic properties, structure, and phase composition have been studied before and after fast-neutron irradiation to a fluence of 1.2 × 1020 n/cm2. Before irradiation, it is the Nd2Fe14B-type phase (space group P42/mnm) that is mainly present in the RQ a...
Article
Samples of polyoxometalate Mo72Fe30: [Mo72Fe30O252(CH3COO)12{Mo2O7(H2O)}2 {H2Mo2O8(H2O)}(H2O)91] · ≈150H2O with a buckyball structure, which can be both crystalline and amorphous, were synthesized. It was shown that such samples can be studied by neutron diffraction. The stability of Mo72Fe30 to heating and UV light exposure (in poly(vinyl alcohol)...
Article
Neutron-diffraction studies of a single crystal of TbNi5 have been performed. Temperature and field dependences of the intensities of the Bragg reflection (001) and magnetic satellites (001)− and (001)+ have been determined. In the temperature range of 7–10 K, sharp changes in the intensities of both the Bragg reflection and its satellites have bee...
Article
Full-text available
Composites of highly exfoliated graphite (HEG) with iron, cobalt, nickel, manganese and their several compounds have been prepared and studied by X-ray and neutron diffraction. Metal phases that are not observed for the bulk metals at room temperature were found in the prepared composites. The HEG-Co composite contained two phases: one of them was...
Article
Full-text available
Solid solutions of the ZrO2-CaO system with 7, 9.6, and 20 mol % of calcium oxide are analyzed by X-ray and neutron diffraction and small-angle neutron scattering. Samples are synthesized by the sol-gel method and annealed at the temperature T = 600°C for 4 h. All samples have a tetragonal structure (P42/nmc space group). The size of crystallites i...
Article
Full-text available
Six samples of Nd-Fe-B-permanent magnets, distinguished in the texture degree, have been measured by neutron diffraction in the reflection and transmission regimes. The texture in the samples was formed by application of impulses of external magnetic field µ 0 H = 4 T. Analysis of the obtained neutron diagrams by means of the Fullprof program allow...
Article
Nano-sized Cu(x)Ni(x)Zn(1-x-y)Fe2O4 ferrites were prepared by using self-propagating high-temperature synthesis (SHS) and mechanical ball milling. As oxygen pressure increases and copper content decreases in the initial composition, average combustion temperature and combustion velocity increases in the ranges of 947 to 1150 degrees C and 4.2 to 6....
Article
The structure of the title compounds is determined by X-ray and high-resolution neutron powder diffraction at 450 K.
Article
Full-text available
The specific features of the crystal structure and the magnetic state of stoichiometric lithium manganite in the structurally ordered Li[Mn2]O4 and disordered Li1 − δMnδ[Mn2 − δLiδ]O4 (δ = 1/6) states have been investigated using neutron diffraction, X-ray diffraction, and magnetic methods. The structurally disordered state of the manganite was ach...
Article
The Tm2Fe17 compound has been studied by means of powder neutron diffraction. The compound undergoes a spin-reorientation transition (SRT) of the “easy axis – easy plane” type with increasing temperature from 75 K to 100 K. The SRT is accompanied by a distinct anomaly in the temperature dependencies of the Tm- and Fe-ion magnetizations, significati...
Article
We studied crystal structure and deuterium (hydrogen) ordering in the ErFe2D3.1 and ErFe2H3.1 compounds by means of X-ray and high-resolution neutron powder diffraction at 450 K. It was found that the structure of these compounds is ascribed to the F23 space group, which is a subgroup of the Fd3m group commonly applied for the RFe2H3-type hydrides....
Article
Full-text available
The magnetic structure of intermetallic compounds Ce2Fe17 − x Mn x (0 ≤ x ≤ 3) was studied using neutron diffraction. The neutron diffraction patterns measured at 4.2 K contain satellites indicating a modulated structure with the wave vector k = [0, 0, τ]. As the concentration x increases, the value of τ increases, while the average magnetic moment...
Article
Full-text available
The structure and magnetic properties of TbNi2Mnx compounds have been studied by the X-ray and neutron powder diffraction, magnetization and magnetostriction measurements. It was found that the compounds for x < 1 crystallize in a cubic MgCu2 Laves phase structure, in spite of the R to 3d-metal ratio changes from 1:2 to 1:3. TbNi2Mn shows a superst...
Article
Full-text available
Magnetic structures and properties of the quasi-ternary layered intermetallic La1-xDyxMn2Si2 (0 ≤ x ≤ 1) compounds were investigated using magnetic measurements on single crystals and neutron powder diffraction. It was shown that various magnetic structures and magnetic phase transitions, which are observed in the compounds with different Dy conten...
Article
We have studied TbxEr1-xNi5 ( x=0 , 0.1, 0.2, 0.3, 0.4, 0.6, 0.8, 0.925, and 1.0) compounds by using several experimental techniques such as ac-susceptibility, heat-capacity, and neutron-diffraction measurements. All the compounds are found to crystallize in the CaCu5 -type structure with space group P6/mmm . The a axis shows a linear increase with...
Article
The crystal and magnetic structures of the TbNi2Mn compound have been refined by the Rietveld analysis of neutron powder-diffraction data. The compound has a cubic C15b-type structure, in which Mn atoms partially occupy both the 4a and 16e sites. Bulk magnetization measurements revealed magnetic ordering below the Curie temperature TC=142K . The va...
Article
Full-text available
Structural changes and the formation of metastable phase states in an Ni3Al-based intermetallic alloy after short-term 5-h annealing at a temperature of 1000°C and upon subsequent multiple deformation of the crystal by compression to 38% at room temperature have been analyzed using transmission electron microscopy and neutron diffraction.
Article
Full-text available
In order to understand the unusual magnetic phase of multiferroic hexagonal manganites, we have investigated the doping effects of hexagonal manganites YMn0.9X0.1O3 ( X=Al , Ru, and Zn) by using bulk measurements as well as neutron-diffraction experiments. We have also re-examined the magnetic structure of YMnO3 to find that it has mainly the Gamma...
Article
The structure of a turbine blade produced from high-temperature nickel alloy ÉP-800 is studied after an impact. The special features of the twinning process in the alloy are studied under conditions of dynamic loading.
Article
Full-text available
Using X-ray, elastic neutron diffraction (END) and small angular neutron scattering (SANS) methods (Diffractometers D2 and D3 respectively), transmitting electronic microscopy (JEOL JEM-200CX) and magnetometry technique (vibrating sample magnetometer -VSM) the structure and magnetic properties of the rapidly quenched (RQ) alloys of the following co...
Article
Full-text available
The motion of atoms in a solid always responds to cooling or heating in a way that is consistent with the symmetry of the given space group of the solid to which they belong. When the atoms move, the electronic structure of the solid changes, leading to different physical properties. Therefore, the determination of where atoms are and what atoms do...