bluuebunny/crossref_metadata_2025 huggingface dataset:
Magnetocaloric Effect and Frustrations in One-Dimensional Magnets
Authors: Zarubin Alexander V. , Kassan-Ogly Felix A. , Medvedev M.V. , Proshkin A.I.
Published: July 2015

In this paper, we investigated the magnetocaloric effect (MCE) in one-dimensional magnets with different types of ordering in the Ising model, Heisenberg, XY-model, the standard, planar, and modified Potts models. Exact analytical solutions to MCE as functions of exchange parameters, temperature, values and directions of an external magnetic field are obtained. The temperature and magnetic field dependences of MCE in the presence of frustrations in the system in a magnetic field are numerically computed in detail.
Magnetic Properties and Magnetostriction of R2Fe17H3±x (R = Tb, Dy) Hydrides
Authors: Tereshina I.S. , Tereshina Evgeniya A. , Doerr Mathias , Pelevin Ivan A. , Telegina Inna V. , Smarzhevskaya Aleksandra I. , Drulis Henry
Published: July 2015

The magnetic anisotropy (MA) of trihydrides of single-crystalline rare-earth (R) intermetallics R2Fe17H3±x (R = Tb and Dy) with small deviations in the hydrogen concentration (x = 0 – 0.4) was investigated via the magnetic and magnetoelastic measurements in a wide temperature region. The easy-axis MA of Tb2Fe17H3±x is preserved in the entire range of magnetically ordered state while an “easy-cone – easy-plane” transition takes place in Dy2Fe17H3±x above ambient temperatures. The trihydrides demonstrate a significant decrease of magnetic anisotropy as the temperature increases. The temperature variation of thermal expansion of Dy2Fe17H3 displays anomalies in the vicinity of a spin-reorientation transition. The longitudinal magnetostriction λ||(T) of the same compound changes its sign at 340 K. The compounds studied can find specific applications in practice.
High Temperature Properties of CoFe/CoNi and Fe/CoNi Biphase Microwires
Authors: Iglesias Irene , El Kammouni Rhimou , Chichay Kseniay , Vazquez Manuel , Rodionova Valeria
Published: July 2015

The objective of this work has been to analyze the high-temperature behavior of magnetically single-and biphase microwires because of its interest from fundamental and applications viewpoints. Two alloy compositions with amorphous structure covered by glass have been prepared as magnetically single phase microwires by quenching & drawing technique: CoFe-based with near zero saturation magnetostriction constant and Fe-based with positive saturation magnetostriction constant. The same wires were used as the core for magnetically biphase microwires. Second CoNi phase was deposited by electroplating. Magnitudes as saturation magnetization and hysteresis parameters are determined in the temperature range from room temperature up to 1200 K. We proceed to a comparative analysis of their magnetic behaviour at different temperatures as well as after cooling down to room temperature. Information on the Curie temperature of different phases and on the influence of heating process on the magnetic properties is thus derived.
Pressure Effects on Transport Properties of (La0.85Sr0.15)yMnO3 Single Crystals
Authors: Shakin Aleksandr , Abashev Denis , Shulyatev Dmitry , Privezentsev Roman , Andreev Nikolay , Mukovskii Yakov
Published: July 2015

We have studied single crystals with same La/Sr ratio but different initial Mn concentration, namely (La0.85Sr0.15)0.93MnO3and (La0.85Sr0.15)0.97MnO3. We have observed, that the temperature of insulator-metal transition TIMincreases for both samples and the temperature of charge ordering TCOincreases for (La0.85Sr0.15)0.93MnO3and decreases for (La0.85Sr0.15)0.97MnO3with the external hydrostatic pressure in the range of 0.1 MPa - 1.3 GPa. After analysis of obtained dependence, we have concluded that (La0.85Sr0.15)0.97MnO3sample has higher concentration of Mn vacancy. Thereby we suppose that growth of Mn vacancy concentration decreases transfer interaction of the conducting electrons and enhances charge ordering of Mn3+and Mn4+ions.
Structural and Magnetic Properties of Fe73,5Si13,5B9Nb3Cu1 Microwires Produced by Modernized Ulitovsky-Taylor Method
Authors: Shalygina Elena E. , Shalygin Aleksander N. , Kharlamova Anna M. , Molokanov Vaycheslav V. , Chueva Tatiana R. , Umnov Pavel P. , Umnova Nadejda V.
Published: July 2015

Results of the investigation of the mechanical, elastic and magnetic characteristics of the “thick” Fe73,5Si13,5B9Nb3Cu1 amorphous microwires, produced by the modernized Ulitovsky–Taylor method, are presented. The cores of the Fe73,5Si13,5B9Nb3Cu1 microwires were found to have the stable geometric parameters along their length and the smooth (almost without defects) surface. The microwires are characterized by the high plasticity and the high strength. The stable geometric parameters of the Fe73,5Si13,5B9Nb3Cu1 microwires along their lengths cause the slight dispersion of magnetic anisotropy of the near-surface layers. As a result, the microwires exhibit the high homogeneity of the near-surface local magnetic properties. The strong influence of the stretching and torsion tensions on the remagnetization signal of the microwires was discovered.
Effect of Current Annealing on Domain Wall Dynamics in Bistable FeCoMoB Microwires
Authors: Klein Peter , Varga Rastislav , Komanicky Vladimir , Badini-Confalonieri Giovanni , Vázquez Manuel
Published: July 2015

We have studied effect of current annealing on domain wall dynamics of FeCoMoB microwires. It was showed that 10 minutes of current annealing corresponds to 1 hour of classical annealing in furnace. Moreover, electrical current flowing through microwire produces Oersted magnetic field and therefore circular magnetic anisotropy is induced during annealing. As a result, induced circular magnetic anisotropy prefers vortex domain wall with velocities up to 3 km/s that can be observed in the current annealed nanocrystalline FeCoMoB microwires with much higher temperature stability.
Magnetic Properties of Magnetic Hydrogels
Authors: Nikitin L.V. , Gladkov A.A. , Korovushkin A.E.
Published: July 2015

Several samples of magnetic hydrogels (also known as ferrogels) are prepared, and their magnetic properties are examined. Polyacrylamide gel is used as the base. Gel matrices are filled with the nanopowder: iron particles with the mean size about 30 nm. The magnetization curves of the samples are measured at different stages of de-swelling. The dependencies of such parameters of magnetization curves as coercive field, remanent magnetization from concentration of magnetic particles in the sample along the process of drying were investigated.
Optical Properties of Aggregated Magnetic Fluid: Birefringence and Light Scattering
Authors: Yerin Constantine V.
Published: July 2015

The optical properties of colloidal solutions of nanosized magnetite particles in kerosene were studied by optical methods (birefringence and light scattering). The data on the birefringence kinetics in nonstationary magnetic fields is used to determine the size distribution of magnetite particles and aggregates. It is shown that the particle size distribution essentially depends on the type of magnetic moments of the particles and aggregates. Static and dynamic light scattering experiments confirm the conclusion about the existence of a significant fraction of nanoparticles in the form of aggregates with sizes of several tens of nanometers.
Structural Organization in Magnetic Fluids with Magnetized Aggregates in Rotating Magnetic Field
Authors: Gladkikh Dmitry V. , Dikansky Yury I. , Kolesnikova Anastasia A.
Published: July 2015

The results of the study of structures forming in magnetic colloids with magnetized aggregates under the action of an elliptically polarized rotating magnetic field are discussed. When a magnetic colloid layer with magnetized aggregates is affected by an elliptically polarized rotating magnetic field, some ordering of the structural lattice is observed, which is determined by the frequency and orientation of the rotating magnetic field polarization ellipse as well as by the value of an additionally imposed steady magnetic field.
Structure Properties in a Bidisperse Ferrofluid in the Absence of an External Magnetic Field
Authors: Nekhoroshkova Yuliya E. , Elfimova Ekaterina A.
Published: July 2015

The structure properties of a ferrofluid modeled by a bidisperse system of dipolar hardspheres are studied theoretically for the case of zero external field. Analytical expressions are providedfor the pair distribution function (PDF) and structure factor (SF) to within the first order in numberdensity and the second order in dipole-dipole interaction strength. The influence of the granulometriccomposition on the behavior of the PDF and the position of the first peak of the SF is analyzed.
The Study of the Mobility Coefficient for Chain Aggregates in Quasi-Two-Dimensional Samples of Magnetic Fluids
Authors: Muratova Alla
Published: July 2015

The paper deals with the study of the mobility coefficients for the chain aggregates of different structures in quasi-two-dimensional magnetic fluids. Note that the quasi-two-dimensional samples contain rings also, not only chains, but this work is devoted to the investigation of the chain mobility only. We have used the Density Functional Theory to obtain the equilibrium concentrations for chain aggregates of different structures. When we know the concentrations we can obtain the mobility coefficients of chains.
The Influence of a Rotating Magnetic Field on the Sample with Magnetizable Materials near the Vessel Bottom
Authors: Pelevina Daria , Turkov Vladimir , Kalmykov Sergey , Naletova Vera
Published: July 2015

The rotation and translational motion of the samples with a magnetizable material alonga bottom of a vessel in a uniform applied rotating magnetic field are examined experimentally. Weconsider a magnetic fluid (MF) drop and a body with a magnetizable polymer (MP). The phenomenaof the change of the direction of the translation motion at some field frequency is observed only forthe MF drop.
Magnetic Field Tunable Electromechanical Resonance Properties of Magnetoelectric Bilayer
Authors: Petrov Roman V. , Petrov Vladimir M. , Kovalenko Denis V. , Semenov Gennady A. , Bichurin Mirza I.
Published: July 2015

The present paper focuses on the magnetoelectric coupling in dimensionally graded ferrite-piezoelectric bilayers in the electromechanical resonance region. Using the bilayer as a transducer which converts the ac magnetic field into an ac electric field shows that the transmission coefficient equals approximately -83 dB for zero bias magnetic field and -44 dB for bias field of 340 Oe. Thus, applying the DC field enables one to obtain the transmission coefficient variation range of 39 dB for the investigated structure. The phenomenon is of importance for the realization of multifunctional magnetoelectric devices including sensors and transducers operating at microwave frequencies.
Temperature Characteristics of Magnetoelectric Effect in Bilayer Ferromagnetic-Piezoelectric Structures
Authors: Burdin Dmitry , Chashin Dmitry , Ekonomov Nikolay , Fetisov Yuri
Published: July 2015

Temperature characteristics of resonant magnetoelectric effect in bilayer structures consisting of langatate, lead zirconate titanate, nickel, and amorphous ferromagnetic Metglas layers have been investigated. The measurements were performed in the temperature range of 150-400 K. The influence of the ferromagnetic and piezoelectric layer’s parameters on the temperature dependence of resonant frequency and magnetoelectric coefficient αE has been demonstrated. The results can be used to develop magnetoelectric magnetic field sensors.
Charge Ordering of Multiferroic LuFe2O4: Influence of Doping and Electric Field
Authors: Maslov Dmitry Andreevich , Kudasov Yuri Borislavovich
Published: July 2015

Charge ordering of nonstoichiometric LuFe2O4+δ is discussed. Properties of triangular bilayer are investigated via mean field theory with Coulomb interaction between sites. It is shown that low temperature state of bilayer has dipole moment essentially under any doping parameter. Correlation between sites in neighbor layers is estimated and dimer partially disordered antiferroelectric phase is extended for the case of nonstoichiometric samples. Competition of correlation effect with bilayer interaction and external electric field is discussed. Phase diagrams for doped specimen are presented. The results of investigation are used to clarify a significant surface impact.
Edge Rotational Magnons in Magnonic Crystals
Authors: Lisenkov Ivan , Kalyabin Dmitry , Nikitov S.
Published: July 2015

It is predicted that in 2D magnonic crystals the edge rotational magnons of forward vol-ume magnetostatic spin waves can exist. Under certain conditions locally bounded magnons may ap-pear within the crystal consisting of the ferromagnetic matrix and periodically inserted magnetic/non-magnetic inclusions. It is also shown that interplay of different resonances in 2D magnonic crystalmay provide conditions for spin wave modes existence with negative group velocity.
Spin-Injection Stimulated Radiation of Terahertz Waves in Magnetic Junctions (“Twaser” Action)
Authors: Chernych A.V. , Chigarev Sergey G. , Gulyaev Yu.V. , Mikhailov G.M. , Panas A.I. , Vilkov Evgeniy Alexandrovich , Zilberman P.E.
Published: July 2015

We report on apparently the first observation of terahertz stimulated radiation in magnetic junctions due to nonequilibrium spins injected by current at room temperatures. The contact between ferromagnetic layers is investigated and so the contact between ferromagnetic and antiferromagnetic layers. The current flowing in the structure creates an inversed population of spin energy levels. After a placing of such a structure in a resonator positive feedback and stimulated emission appears. When current is growing, we observe the relatively narrow (in frequencies) peak - analogous to laser generation but at terahertz frequencies. For the higher currents we observe the picture of electromagnetic turbulence.
Numerical Simulation of Spin Torque Induced by Spin Hall Effect in CuPt/Fe Heterostructure
Authors: Andrianov Timofey , Gritsenko Yulia , Strelkov Nikita , Ryzhanova Natalia , Vedyaev Anatoly
Published: July 2015

Spin transport and distribution of spin accumulation in CuPt/Fe heterostructure are numerically investigated, using linearized Levy-Fert model. It was shown that Spin Hall Effect in CuPt layer produces non-equilibrium spin accumulation in adjacent ferromagnetic layer. Spin accumulation vector is not collinear with the direction of magnetization in ferromagnetic layer which leads to the appearance of spin transfer torque. The absolute values and angular dependence of this torque were calculated and it was demonstrated that for the current the values of torques are sufficient for manipulation of magnetization of ferromagnetic layer.
Structural, Magnetic and Electric Transport Properties for Co2FeAl0.5Si0.5/n-GaAs Junctions
Authors: Tezuka Nobuki , Saito Tatsuya , Matsuura Masashi , Sugimoto Satoshi
Published: July 2015

The authors have been investigated structural, magnetic and electrical transport properties for CFAS/n-GaAs junctions. From cross sectional TEM image, RHEED and XRD patternz of thin CFAS films, CFAS films found to be grown epitaxially on GaAs, and shown L21-ordered structure for the films with substrate temperature (TCFAS) of 300°C and 400°C. It is hard to find some additional phase around the interface between CFAS and GaAs. Magnetic moment (and magnetic anisotropy energy) of CFAS increased (and decreased) with increasingTCFASup to 300°C and decreased (and increased) atTCFASof 400°C, respectively. The asymmetry of current (J)-voltage (V) curve for the junction withTCFAS=300°C was found to be larger than those for other junctions. It was found there is the relation betweenTCFASdependence of spin signal obtained by three terminal Hanle or four terminal non-local measurement and that of magnetic moment, magnetic anisotropy field or asymmetry ofJ-Vcurve.
Magnetoresistance and Magnetic Properties CexMn1-xS
Authors: Aplesnin Sergei S. , Sitnikov Maksim N. , Romanova Oksana B. , Eremin Evgeniy V. , Sokolov Vladimir V. , Pichugin Andrei Yu.
Published: July 2015

The transport and magnetic properties of cation-substituted manganese sulphides CexMn1-ХS in the 4K - 450K temperature range in magnetic fields up to 90 kOe are studied. The hysteresis of curve magnetization for X=0.01 and nonlinear field behavior of the magnetization at X = 0.05, the sharp Curie temperature drop were found. The sharp maximum in the temperature dependence of resistivity was observed. The shift of the maximum temperature to low temperatures at cerium ion concentration increasing and in magnetic field was established. Model of orbital polaron for explanation of experimental datа was used.
Finite Size Effects in Magnetic Multilayers Induced by Interaction with the Substrate
Authors: Kostyuchenko M.V.
Published: July 2015

The technique of finite difference equations is used for analytical investigation of magnetization pattern in magnetic multilayers. The magnetic multilayers with equal magnetic layers and ferrimagnetic multilayers are considered. Heisenberg and biquadratic exchange interactions and uniaxial anisotropy are taken into account. The analytical dependencies of total magnetic moment on external magnetic field are obtained taking into account the strong interaction with the substrate. The significant difference in the behavior of magnetic moment is derived for ferrimagnetic multilayers with odd and even layers number.
Bifurcations in the Dynamical System for Three-Layered Magnetic Valve
Authors: Ostrovskaya Natalia , Skidanov Vladimir , Iusipova Iuliia
Published: July 2015

Magnetization dynamics in a three-layered nanopillar Co/Cu/Co structure with one fixed and one free layer driven by external magnetic field and spin-polarized electric current was investigated using methods of the theory of bifurcations. Mathematical model is based on the Landau-Lifshits-Gilbert equation with the current term in the Sloncžewski–Berger form. Orientation of applied magnetic field was considered to be parallel to the anisotropy axis. Physical model included the magnetocrystalline anisotropy field and the demagnetizing field. Because of small size of the structure, the space dependence of magnetization, as usually, was not taken into account. The resulting system of equations has the form of the nonlinear dynamical system with the polynomial right sides. Mathematical simulation of magnetization dynamics for several typical values of field and current was performed. The numerical experiments revealed the features of switching process in more detail and permitted to find new regimes of magnetization dynamics, such as incomplete and accidental switching.
Ferromagnetic State of LaMnO3 Interlayer in La0.7Sr0.3MnO3/LaMnO3/SrRuO3 Heterostructures
Authors: Petrzhik Andrey M. , Khaydukov Yury N. , Mustafa Luqman , Demidov Victor V. , Ovsyannikov Gennady A.
Published: July 2015

Magnetic state of epitaxial heterostructures La0.7Sr0.3MnO3/LaMnO3/SrRuO3 (LSMO/LMO/SRO) was studied by SQUID magnetometer, ferromagnetic resonance (FMR) and polarized neutron reflectometry (PNR) techniques. The fit of PNR and FMR data give us the magnetization of each layer, while the SQUID gives the total magnetization of our structures. The magnetic moment of the LMO layer has the magnetization 4πMLMO=4.2kGs (2.4 mB/Mn) at T=140K according to our PNR data fitting.
Peculiarities of Transport, Resonance and Optical Properties of the Anion-Substituted Manganese Chalcogenides
Authors: Romanova O.B. , Aplesnin Sergei S. , Vorotynov A.M. , Makovetskii G.I. , Demidenko O.F. , Yanushkevich K.I.
Published: July 2015

The transport, resonance and optical properties of anion-substituted manganese chalcogenides MnSe1-xTex in the 77-300 K temperature range in magnetic fields up to 1T are studied. The magnetoresistance effect with the maximum value in the vicinity of the Neel temperature for the composition x = 0.1 is revealed. EPR data indirectly indicate the type of the current carriers – lattice polarons. The changes in electron structure occurring due to the anionic substitution are studied using the optical methods.
High-Frequency Properties of Multilayer Systems Based on the (Co41Fe39B20)X(SiO2)100-X and (Co45Fe45Zr10)X(Al2O3)100-X Nanocomposites
Authors: Al Azzawi Haider , Kalinin Yuri , Sitnikov Alexander , Tarasova Oksana
Published: July 2015

New {[({[(Co41Fe39B20)X(SiO2)100X]/[(Co41Fe39B20)X(SiO2)100х+O2]}178 and {[(Co45Fe45Zr10)X(Al2O3)100-X]/[(Co45Fe45Zr10)X(Al2O3)100-X+O2]}300 multilayer heterogeneous structure has been obtained by ion-beam sputtering method. Magnetostatic and magnetodynamic properties and the structure of the nanocomposites have been investigated. It was shown that, the oxidized interlayer composite adding lead to suppression of perpendicular magnetic anisotropy component, and a change in the magnetic structure of the composites, which determines the change in the frequency dependence of the real (μ/) and imaginary (μ//) parts of the complex permeability.
Green’s Functions of Spin and Electromagnetic Waves in the Sinusoidal Superlattice
Authors: Ignatchenko Valter A. , Tsikalov Denis S.
Published: July 2015

The problem of finding the Green's function of spin and electromagnetic waves in the sinusoidal superlattice is considered. An analytical expression for the spectral representation of the Green's function has been found in the form of ascending continued fractions, the particular denominators of which are ordinary continued fractions. The Green’s function in the-space has been found by the numerical Fourier transformation of the Greens’s function found in the spectral representation.
Hypersound Excitation in the Ferrite Plate by Impulse Magnetization Reversal
Authors: Vlasov Vladimir S. , Pleshev D.A. , Kotov Leonid N. , Shavrov Vladimir G. , Shcheglov V.I. , Asadullin F.F. , Poleshikov S.M.
Published: July 2015

Excitation of hypersound elastic oscillations in the microwave on the magnetization reversal of the normal magnetized ferrite plate is studied in the paper. Characteristic times of the process of development of magnetic and elastic oscillations were revealed. Their relation to the parameters of the magnetic and elastic damping has been revealed.
AC Magnetic Susceptibility Study in Co/Au Nanoparticles
Authors: Hrubovčák Pavol , Zeleňáková Adriana , Zeleňák Vladimír , Michalíková Jana
Published: July 2015

In this work we report the study of magnetic relaxation process presented in the bimetallic Co/Au nanoparticles prepared utilizing the reverse micelle method. Structural analysis of the system using synchrotron X-ray diffraction and transmission electron microscopy documented individual nanocrystalline particles of average size about 7 nm. Magnetic properties of the particles were examined by ac magnetic susceptibility measurements at temperature range 2 – 300 K at different frequencies of magnetic field. The relaxation process was revealed at temperature about 6 K. Application of several theoretical models on experimental data of magnetic susceptibility confirmed strong inter-particle interactions and novel superspin glass state in the nanoparticle system at low temperatures.
Peculiarities of the Interface Forming in the “Nanocomposite-Bismuth Telluride” Multilayer System
Authors: Zykov G.S. , Gan'shina E.A. , Novikov A.I. , Kalinin Yu.E. , Sitnikov A.V.
Published: July 2015

The research of magneto-optical properties has been conducted for the “Nanocomposite-bismuth telluride” (Co40Fe40B20)33.9(SiO2)66.1/[Te3Bi2] multilayer system at various thicknesses of each layer type. We report an enormous enhancement of magneto-optical (MO) response in this system. Besides, a good correlation between thickness dependences of transversal Kerr effect (TKE) and magneto-transport properties has been established. Such correlation was related to peculiarities of the interface forming process at the ferromagnetic (FM) granule boundaries. Moreover, this amplification of magneto-optical response is largest among the other spacer layers, such as Si, Cu, and C, therefore a comparison between them has been plotted.
Room Temperature Instability of Exchange Anisotropy in FeMn/FeCo System
Authors: Jiménez Erika , Mikuszeit Nikolai , Cavicchia Demetrio R. , Rossi Lorella , D'Orazio Franco
Published: July 2015

Ferromagnetic (FM) FeCo is investigated in exchange bias systems. The ferromagnetic layer is grown on a FeMn antiferromagnetic (AFM) layer. Partial superficial oxidation of FeCo is observed. The standard field cooling procedure results in a large room temperature exchange bias effect. However, the training effect observed when the hysteresis loops are repeated does not have a saturating trend. This behavior is related to the evolution of pinned moments at the FM/AFM interface. X-ray circular magnetic dichroism technique is used to clarify this mechanism.
Resonant Dynamics of the Domain Walls in Multilayer Ferromagnetic Structure
Authors: Ekomasov Evgeniy G. , Gumerov Azamat M. , Murtazin Ramil R. , Kudryavtsev Roman V. , Ekomasov Andrey E. , Abakumova Natalya N.
Published: July 2015

The domain walls dynamics and generation and evolution of magnetic inhomogeneities of soliton type, emerging in a thin flat layer with the parameters of the magnetic anisotropy, which are different from other two thick layers of the five-layer ferromagnetic structure, were investigated.
Temperature Behavior of Magnetization in Multiphase Co-P Powders in Unsaturated Regime
Authors: Li Oksana Anatoljevna , Komogortsev Sergey Viktorovich , Iskhakov Rauf S. , Chekanova Lidia Aleksandrovna , Eremin Evgeniy V.
Published: July 2015

In this paper we have proposed a modified expression for the fitting M(T) data in Co-P powders with nanocorundum and nanodiamond precipitates. The expression for M(T) takes into account the effects from both thermal magnetic excitations – Bloch’s T 3/2 law and temperature dependence of the magnetic anisotropy. The fitting parameters are spontaneous magnetization at absolute zero temperature, Bloch constant and order of magnetic anisotropy constant. The obtained Bloch constant is in good agreement with literature data. The order of magnetic anisotropy constant is found to be about 3 that is surprising result and supposedly comes from multiphase nature of the investigated Co-P powder.
Oxygen Effect on Magnetic Anisotropy Energy of Co Nanowires on Cu(210) Surface - An Ab Initio Study
Authors: Korobova Julia , Bazhanov Dmitry , Kamynina Irina
Published: July 2015

An ab initio study of Co monatomic nanowires (NW) magnetic properties on pure and oxygen reconstructed Cu (210) surface was performed. Strong influence of oxygen surface impurity on MAE in Co nanowire was found. High value of magnetic moment and small energy of magnetic anisotropy (MAE) were obtained in Co nanowires on pure Cu (210) surface. After oxygen reconstruction of Cu (210) surface (Cu (210)-(2×1)O) the significant enhancement of MAE was found in Co nanowires, while the magnetic moment of Co atoms is practically unchanged. Oxygen on Cu (210) surface rotates easy magnetization axis in Co NW with respect to the pure surface.
Magnetic Resonance in CuCr2S4 Nanoclusters and Nanocrystals
Authors: Pankrats Anatolii , Vorotynov Alexander , Tugarinov Vasilii , Zharkov Sergey , Abramova Galina , Zeer Galina , Ramasamy Karthik , Gupta Arunava
Published: July 2015

Nanoclusters and nanocrystals of the room temperature magnetic spinel CuCr2S4 synthesized using a facile solution-based method were examined by magnetic resonance in a wide frequency range 9.6÷80 GHz and at temperatures down to 4.2 K. Decreasing of the resonance field and broadening of the resonance lines are found below ∼ 50 K for both the nanocluster and nanocube samples due to the freezing of magnetic moments of nanocubes and nanocrystalline particles constituting nanoclusters. Additional blocking temperature Tb≅300 K appears in nanoclusters due to the freezing of the magnetic moment of the entire cluster as a whole. Below this temperature, an additional low-field resonance line is found in the resonance spectra of nanoclusters at X-band.
Ab Initio Study of the Oxygen Effect on Magnetic Interactions within 3d Metal Nanowires on Vicinal Rh (553) Surface
Authors: Kamynina Irina , Bazhanov Dmitry , Korobova Julia
Published: July 2015

We present ab initio study of the magnetic properties of monatomic 3d transition metal (Mn, Fe, Co, Ni) nanowires without and with oxygen atoms on vicinal Rh (553) surface. We considered different experimentally observed submonolayer quantities of oxygen atoms. It was found that monatomic 3d metal nanowires without oxygen are in magnetic states. Within oxidized metal nanowires oxygen atoms affect on the magnetic moments and magnetic interaction of metal atoms. This influence leads to reduced (in the case of Mn, Fe and Co atoms) or quenched (in the case of Ni atoms) magnetic moment for these metal atoms.
Anisotropy in FeCo Nanoparticles, a First Step
Authors: Khadra Ghassan , Tamion Alexandre , Tornus Florent , Canut Bruno , Dupuis Veronique
Published: July 2015

In this article, we study the intrinsic magnetic properties of diluted FeCo clusters nanoparticles embedded in an inert amorphous carbon matrix. We report an enhancement of the magnetic anisotropy energy (MAE) after annealing demonstrated by superconducting quantum interference device (SQUID) measurements and adjustments. Rutherford backscattering spectrometry (RBS) was used to quantify the sample stoichiometry and concentration.
Dependence of the Hysteresis Characteristics of Co-Au Core-Shell Nanoparticles on the Size of the Particles
Authors: Chernova Maria A. , Afremov Leonid L. , Iliushin Ilia G.
Published: July 2015

Hysteresis loops were plotted and dependence of coercive field, residual saturation magnetization and saturation magnetization on size of the Co-Au core-shell nanoparticles were calculated within the developed model. It was shown that decrease in the size of nanoparticles leads to decrease of the abovementioned characteristics. Calculated values of the hysteresis characteristics ​​are in good agreement with the experimental data.
Easy Axis Spin-Flop in ε-Phase In-Doped Iron (III) Oxide Nanowires
Authors: Dmitriev A.I. , Koplak O.V. , Namai Asuka , Tokoro Hiroko , Ohkoshi Shinichi , Morgunov R.B.
Published: July 2015

This work reports study of magnetic properties of the ε-In0.24Fe1.76O3 nanowires possessing 6 kOe coercive force at room temperature. Freezing of the sample below 190 K causes sharp decrease of the coercive force and magnetization of nanowires driven by the easy axis spin-flop transition.
Free-Standing 2D Silicon Nanocrystals Stabilized with Perfluorophenyl Ligands: Experiment and Ab Initio Research
Authors: Aslanov Leonid , Kudryavtsev Igor , Zakharov Valery , Kulatov Erkin , Uspenskii Yurii
Published: July 2015

Silicon (Si) is currently the basis of most of nanodevice technology, therefore ultrathin materials based on Si have the great advantage of easy integration into existing circuitry. First flat silicon nanoparticles have been obtained with perfluorophenyl (PFPh) ligand coating. The size of these particles varied from 15 to 50 nm. Their thickness evaluated with the atomic force microscopy was about 3.3 nm. Based on ab initio DFT calculations we investigate the geometries and electronic structures of free-standing PFPh-stabilized 2D silicon in order to see if such systems have promising electronic and optical properties. We also examined the effect of doping PFPh-stabilized 2D silicon by the Mn atoms.
Magneto-Optical Properties of Multilayer Nanostructures with Composite Magnetic Layers near Percolation Threshold
Authors: Buravtsova Victoria , Gan’shina Elena , Kalinin Yuri , Sitnikov Alexander , Zubakin Daniil
Published: July 2015

Spectra and field dependencies of Transversal Kerr Effect (TKE) for [(Co45Fe45Zr10)46(Al2O3)54(X)/Si (Y)]nmultilayers (ML) with thin layers (X < 2,5 nm; Y < 3,5 nm) have been studied in the energy range 0,5 – 4,0 eV. It was found that TKE field dependencies in the nearest infrared (IR) and visible energy ranges exhibit anomalous behavior. TKE spectra measured in weak (~30 Oe) and strong (~2 kOe) magnetic fields were essentially different. It was shown that magneto-optical response of multilayered structure composite-silicone is the sum of magnetic composite layers and composites formed on interface contributions. And these contributions may have an opposite sign of TKE. Interface magnetic states depend on composite and semiconductor layers’ thicknesses and FM phase concentration in composite layers.
Nanocrystalline Soft Magnetic (Fe0.7Co0.3)88Hf2W2Mo2Zr1B4Cu1 Alloy with Enhanced Thermal Stability of Magnetic Properties
Authors: Lukshina Vera A. , Dmitrieva Natalia V. , Volkova Elena G. , Potapov Anatolii P. , Filippov Boris N. , Shishkin D.A.
Published: July 2015

Magnetic properties, structure and thermal stability of the (Fe0.7Co0.3)88Hf2W2Mo2Zr1B4Cu1 alloy ribbon after its nanocrystallization at 620-750°C for 0-20 min in the presence or absence of tensile stresses σ were studied. It was shown that under the effect of tensile stresses a longitudinal magnetic anisotropy with an easy magnetization axis parallel to the long size of the ribbon was induced in the alloy. A better thermal stability of magnetic properties was observed for the alloy subjected to the nanocrystallization annealing at 620° for 20 min with σ = 170 MPa. After the subsequent annealing at 570°C for 25 h without σ, the magnetic properties of the alloy are unchanged. Increasing of the nanocrystallization annealing temperature up to 670-750°C did not result in improvement of the thermal stability of magnetic properties.
Micro Grid Frame of Electroless Deposited Co-P Magnetic Tubes
Authors: Chekanova L.A. , Denisova E.A. , Yaroslavtsev Roman N. , Komogortsev S.V. , Velikanov D.A. , Zhizhaev A.M. , Iskhakov R.S.
Published: July 2015

The morphology and magnetic characterization results of electroless deposited CoP coating on the copper microgrid with the mesh size of 50 microns are presented and discussed. The deposited coating is found to be well uniform by the thickness. Magnetic anisotropy in the plane of the grid has been studied by the hysteresis loops and the FMR spectra and discussed with the modeling of the grid as the frame grid system of magnetic tubes.
Ferromagnetic and Spin-Wave Resonance in FexNi1-x (0<x<1) Films
Authors: Vazhenina I.G. , Iskhakov Rauf S. , Chekanova L.A. , Stolyar S.V. , Yakovchuk V.Yu.
Published: July 2015

The ferromagnetic and spin-wave resonance in the electroless deposited thin films of Fe-Ni alloy including alloy with invar content are studied. The dependences of resonance field on the number of mode extracted from spin-wave resonance spectra are deviated from the Kittel dispersion relation. The type and the size of magnetic heterogeneity are estimated in accordance with the spin-wave spectroscopy technique.
Copper Oxide Superconducting/Antiferromagnetic Interface
Authors: Kislinskii Yulii , Constantinian Karen , Ovsyannikov Gennady , Shadrin Anton , Borisenko Igor , Khaydukov Yuri , Sheyerman Alexander , Vasiliev Aleksandr
Published: July 2015

Superconducting Nb/Au/Ca1-xSrxCuO2/YBa2Cu3O7mesa-heterostructures were investigated. Dependencies of electrical parameters versus inverse capacitance were measured. A band diagram which takes into account an accumulation of holes in Ca1-xSrxCuO2interlayer and band bending due to difference of work functions was proposed. The dependencies of electrical parameters were analyzed by examining the quasipartical and superconducting currents.
Role of Interface Transparency and Exchange Field in the Superconducting Triplet Spin-Valve Effect
Authors: Deminov Rafael G. , Tagirov Lenar R. , Gaifullin Rashid R. , Fominov Yakov V. , Karminskaya Tatyana Yu. , Kupriyanov Mikhail Yu. , Golubov Alexander A.
Published: July 2015

We study the superconducting transition temperatureTcof F2/F1/S trilayers (Fi is a metallic ferromagnet, S is a s-superconductor), where the long-range triplet superconducting component is generated at canted magnetizations of the F layers. In this paper we show that it is possible to realize different spin-valve effect modes - the standard switching effect, the triplet spin-valve effect, reentrantTc(α) dependence or reentrantTc(α) dependence with the inverse switching effect - by variation of the F2/F1 interface transparency or the exchange splitting energy. In addition, we show that positionof theTcminimum can be changed by joint variation of the F2/F1 interface transparency and the layerthicknesses.
Heating of Zn-Substituted Manganese Ferrite Magnetic Nanoparticles in Alternating Magnetic Field
Authors: Elkhova T.M. , Yakushechkina A.K. , Semisalova A.S. , Gun’ko Y.K. , Spichkin Yu.I. , Pyatakov A.P. , Kamilov K.I. , Perov Nikolai S. , Tishin A.M.
Published: July 2015

In this report, were studied the heating capability of magnetic nanoparticles (MNps) made from Zn-substituted manganese ferrite compounds ZnxMn1-xFe2O4 with Zn content varying from 0% to 90%. The MNps of diameter 5-25 nm were synthesized by co-precipitation of metal salt solution with NaOH solution. It was shown, that specific absorption rate (SAR) for the compound with Zn content of 20% is bigger than the other ones exhibited 1.5 W/g. Also SAR for the magnetic liquids made of the MNps shows bigger SAR values, which indicates the Brown relaxation mechanism in the system.
To the Theory of Hyperthermia Effect Induced by Magnetic Nanoparticles
Authors: Zubarev Andrey , Abu-Bakr Ali
Published: July 2015

In this paper, we present results of theoretical modeling of the rise of temperature for the unit of time in a dilute suspension of the fiber ferromagnetic particles under the action of the linearly polarized oscillating magnetic field. Two mechanisms of the heat production, namely the particle rotation in the liquid and its internal remagnetization are considered. We study effect of the particle shape, its magnetic properties and rheological properties of the carrier liquid on the rise of temperature for the unit of time by the particles.
Coarsening in Critical Dynamics of 2D XY-Model
Authors: Popov Ivan , Prudnikov P.
Published: July 2015

In the past few years, systems with slow dynamics have attracted considerable interest. Coarsening effects are exhibited in a wide range of systems. Non-equilibrium critical behavior of 2D XY-model demonstrates slow dynamics in a wide temperature range. The coarsening in pure and diluted 2D XY-model are investigated for various defects concentration. The period of logarithmic grows of cluster size was found.
Autoresonant Excitation of Spin Wave "Dark" Solitons
Authors: Borich M.A. , Tankeev A.P. , Shagalov A.G.
Published: July 2015

In this paper we propose a method to generate pure dark solitons by a periodic external field with a slowly varying frequency, which allows to control amplitude of the excited solitons and period of soliton trains. Our approach to generate dark solitons is based on the effect of autoresonance when the excited wave is phase-locked by the drive after the crossing the resonance. The resonant frequency and the threshold condition on the amplitude of the driving were found.
Phase Transitions in Frustrated Ising Antiferromagnet on a Body-Centered Cubic Lattice with Next-Nearest Neighbor Interactions
Authors: Murtazaev Akay K. , Ramazanov Magomedsheykh K. , Kurbanova Djuma R.
Published: July 2015

The phase transitions in antiferromagnetic Ising model are studied on a body-centered cubic lattice by taking the interactions of next-nearest neighbors into account. The model is investigated on basis of the replica Monte Carlo algorithm and the histogrammic analysis of data. The diagram of the critical temperature dependence on an interaction value of next-nearest neighbors is plotted. The studied model reveals the phase transitions of second order. A static magnetic critical indices is calculated using the finite-dimensional scaling theory.
The Tumor Antigen Cyclin B1 Hosts Multiple CD4 T Cell Epitopes Differently Recognized by Pre-Existing Naive and Memory Cells in Both Healthy and Cancer Donors
Authors: Chevaleyre Claire , Benhamouda Nadine , Favry Emmanuel , Fabre Elizabeth , Mhoumadi Anais , Nozach Hervé , Marcon Elodie , Cosler Guillaume , Vinatier Emeline , Oudard Stephane , Hans Stephane , Le Pimpec-Barthes Françoise , Bats Anne-Sophie , Castelli Florence A. , Tartour Eric , Maillère Bernard
Published: July 2015

Cyclin B1 (CCNB1) is considered as a potential target for a cancer vaccine, as it is overexpressed in many malignant cells, while being transiently expressed in normal cells. To evaluate the CD4 T cell response to CCNB1, we derived T cell lines by multiple weekly rounds of stimulation with recombinant CCNB1 of T cells collected in healthy donors (long-term T cell assays). T cell lines were specific for 15 immunodominant peptides and derived preferentially from naive T cells. From 74 overlapping peptides, 20 peptides were selected for their broad specificity of binding to HLA class II molecules and included most of the immunodominant epitopes. They primed in vitro a large number of specific CD4 T cell lines in all the donors. Immunodominant epitopes were the most efficacious in long-term T cell assays, both in terms of number of specific T cell lines and number of responding donors. The 20 peptides were also submitted to short-term T cell assays using cells collected in healthy and cancer patients with the aim to evaluate the memory response. The recognized peptides differed from the immunodominant peptides and were part of the best promiscuous peptides. We also observed pre-existing CCNB1-specifc IgG Abs in both healthy and cancer donors. Long- and short-term T cell assays revealed that CCNB1 contained many CD4 T cell epitopes, which are differentially recognized by pre-existing naive and memory CD4 T cells. These observations are of value for the design of cancer vaccines.
TLR-9 and IL-15 Synergy Promotes the In Vitro Clonal Expansion of Chronic Lymphocytic Leukemia B Cells
Authors: Mongini Patricia K. A. , Gupta Rashmi , Boyle Erin , Nieto Jennifer , Lee Hyunjoo , Stein Joanna , Bandovic Jela , Stankovic Tatjana , Barrientos Jacqueline , Kolitz Jonathan E. , Allen Steven L. , Rai Kanti , Chu Charles C. , Chiorazzi Nicholas
Published: July 2015

Clinical progression of B cell chronic lymphocytic leukemia (B-CLL) reflects the clone’s Ag receptor (BCR) and involves stroma-dependent B-CLL growth within lymphoid tissue. Uniformly elevated expression of TLR-9, occasional MYD88 mutations, and BCR specificity for DNA or Ags physically linked to DNA together suggest that TLR-9 signaling is important in driving B-CLL growth in patients. Nevertheless, reports of apoptosis after B-CLL exposure to CpG oligodeoxynucleotide (ODN) raised questions about a central role for TLR-9. Because normal memory B cells proliferate vigorously to ODN+IL-15, a cytokine found in stromal cells of bone marrow, lymph nodes, and spleen, we examined whether this was true for B-CLL cells. Through a CFSE-based assay for quantitatively monitoring in vitro clonal proliferation/survival, we show that IL-15 precludes TLR-9–induced apoptosis and permits significant B-CLL clonal expansion regardless of the clone’s BCR mutation status. A robust response to ODN+IL-15 was positively linked to presence of chromosomal anomalies (trisomy-12 or ataxia telangiectasia mutated anomaly + del13q14) and negatively linked to a very high proportion of CD38+ cells within the blood-derived B-CLL population. Furthermore, a clone’s intrinsic potential for in vitro growth correlated directly with doubling time in blood, in the case of B-CLL with Ig H chain V region–unmutated BCR and <30% CD38+ cells in blood. Finally, in vitro high-proliferator status was statistically linked to diminished patient survival. These findings, together with immunohistochemical evidence of apoptotic cells and IL-15–producing cells proximal to B-CLL pseudofollicles in patient spleens, suggest that collaborative ODN and IL-15 signaling may promote in vivo B-CLL growth.
Becoming transdisciplinary theologians: Wentzel van Huyssteen, Paul Cilliers and Constantine Stanislavski
Authors: Loubser Gys
Published: July 2015

Firstly, I discuss deferent descriptions of transdisciplinary research and argue that Wentzel van Huyssteen’s postfoundationalist description of epistemology provides a progenitive epistemology for a variety of transdisciplinary engagements. Secondly, I suggest that complexity, as described by Paul Cilliers, can be rooted in a postfoundationalist epistemology and illuminates the facilitation of transdisciplinary research. Based on this description and facilitation of transdisciplinarity, I argue that transdisciplinary theologians need to be skilled empathisers because knowledge is generated and exchanged by embodied agents, embedded in particular disciplines. In a transversal move I suggest that, given contemporary research on empathic skills and the embodied aspects of empathy, Stanislavski’s approach to the training of actors illuminates a way in which we can train transdisciplinary theologians. The training develops empathetic skills through both mental and embodied exercises and equips students to generate empathy in different contexts without following set rules.
Étude chimique de l’extrait aqueux d’Allium subvillosum (L.) (Alliaceae) et l’évaluation de sa toxicité chez les souris
Authors: Adly Farida , Moussaid Mina , Elamrani Abdel Aziz , Berahal Chadi , Moussaid Hassane , Bourhim Nourdinne , Loutfi Mohammed
Published: July 2015

Allium subvillosum (L.) fait partie de la pharmacopée marocaine, dont les bulbilles sont couramment utilisées comme dépuratifs et antidotes. Nous avons mené une étude chimique et biologique de l’extrait aqueux de la partie souterraine, constituée par des petites bulbilles à odeur d’ails, dont le but est de valoriser cette plante, aussi bien par la caractérisation chimique que l’étude toxicologique, et pour fixer ainsi une marge de sécurité de son emploi par la population locale. Les résultats chimiques obtenus ont révélé la présence des flavonoïdes, des alcaloïdes, des stérols, des triterpènes, des tanins, des composés réducteurs, des hétérosides cardiotonique et des saponosides. Et l’étude de la toxicité aiguë, réalisée chez des souris, a montré que l’extrait aqueux administré par voie intrapéritonéale est moyennement toxique avec une DL50 = 562.34± 342.64 mg/kg du poids corporel (PC). Alors que la même substance est faiblement toxique avec une DL50 = 3235.93 ± 878.34 mg/kg du PC, lorsqu’elle est administrée par voie orale.Mots clés: Pharmacopée marocaine, toxicité aiguë, voie intrapéritonéale, voie orale, phytochimie.
Las tareas de comunicación oral en la evaluación del inglés: el uso de conectores
Authors: Peñate Cabrera Marcos
Published: July 2015

A pesar de que los expertos en evaluación han estado investigando la relación que hay entre los diferentes tipos de tareas y su nivel de dificultad, aún resulta necesario continuar dicho proceso de análisis para poder tener una visión más exacta de las variables que inciden en dicha relación. En este artículo estudiamos los tres tipos de tareas más usadas en los diferentes modelos de pruebas orales (entrevista individual a partir de una foto, entrevista individual a partir de una tira cómica y un diálogo en parejas). Para hacer este estudio evaluamos a 244 alumnos de segundo de bachillerato pertenecientes a nueve centros escolares y con un nivel A2 de inglés. La variable que hemos querido analizar al contrastar los tres tipos de tareas es la de la cantidad y complejidad de la producción oral emitida, que se midió utilizando como referente el uso de conectores y utilizando los test estadísticos de homogeneidad y especificidad.