bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigation on Mechanical Properties and Formability of Cross Roll Rolled Ni-10Cr Alloy
Authors: Song Kuk Hyun , Kim Han Sol , Kim Won Yong
Published: June 2012

This study evaluated the microstructure and mechanical properties enhancement of cross roll rolled Ni-10Cr alloy, comparing with conventional rolled material. Cold rolling was carried out to 90% thickness reduction and subsequently annealed at 700 °C for 30 min to obtain the fully recrystallized microstructure. For annealed materials after rolling, to investigate the grain boundary characteristic distributions, electron back-scattering diffraction technique was introduced. Application of cross roll rolling on Ni-10Cr alloy contributed to the notable grain refinement, consequently, average grain size was refined from 135 μm in initial material to 4.2 μm in cross roll rolled material. These refined grain size led to an enhanced mechanical properties such as yield and tensile strengths. Furthermore, <111>//ND texture in CRR material was well developed than that of CR material, which contributed to the mechanical properties and formability enhancement.
The Rheological Properties of Konjac Glucomannan (KGM) Solution
Authors: He Pan , Luo Xue Gang , Lin Xiao Yan , Zhang Hong Ping
Published: June 2012

The rheological properties of konjac glucomannan (KGM) solution were measured by HAAKE Rotational Rheometer, and the results indicated that KGM solution began to transform from Newtonian fluid to non-Newtonian fluid above 0.10 wt%, which represented the overlap of molecular chains. When the concentration exceeded 1.00 wt%, the entanglements of molecular chains became obvious, and the KGM sol formed. Furthermore, the rheological formulas of KGM solution were simulated very regularly, and the parameters of viscosity (η) and non-Newtonian index (n) held the relationship of exponential function to concentration (C), however, the consistency coefficient (κ) displayed a power function, then their concentration-dependence functions were as follows: η=-0.33+1.17e16.80C, n=0.29+0.79e-2.56C, and κ=29.11C3.17. Finally, the rheological properties from diluted solution to KGM sol were revealed.
Preparation and Application of Electrospinning Membranes of Thermoplastic Carboxymethyl Cellulose/PLA for Removal of Cu2+ from Aqueous Solutions
Authors: Li Ying , Lin Xiao Yan , Chen Zhe , Luo Xue Guang , Zuo Wei Li
Published: June 2012

A composite membrane of thermoplastic carboxymethyl cellulose (TCMC) /PLA was prepared by electrospinning process, and crossliked by epichlorohydrin solution at different temperature. The cross-linking temperature was optimized by characterizing the morphology and tensile strength of the film. The optimal cross-linking temperature was 50°C. A composite membrane was used to remove Cu2+ from aqueous solutions, and the effects of initial concentration of Cu2+ and contact time on the removal efficiency of Cu2+ were investigated. The removal efficiency of Cu2+ was 13.78%, at the initial concentration of 40 mg·L-1 and contact time of 30s.
Research of Low Cost Fracturing Proppant
Authors: Liu Li Xia , Niu Rui Dong , Jin Hai Yun , Lv Bao Qiang , Liu Shun
Published: June 2012

Petroleum has been less and less in the earth. However, only small part of the oil can be withdrawn from the oil well by the traditional method. Hydraulic fracturing is an effective way to improve the production of the oil well, in which the proppant plays an important role. As the low density proppant has the advantages of providing high flow conductivity and decreasing the consumption of the proppant, one kind of low cost and low density ceramic fracturing proppant were developed. The mechanical properties and densities of the samples were measured; then the specimens were identified by XRD and the microstructure was observed by SEM. The result showed that, when using bauxite, quartz, clay and manganese mineral as the main constituent, the ceramic proppant prepared meets the requirements of the Chinese petroleum and natural gas industry standards (SY/T 5108-2006) , in addition, it has the advantage of low cost and low density.
Materials Life Cycle Assessment of Chemical Strengthening Glass Used for Touch Screen Panel
Authors: Lee Na Ri , Lee Soo Sun , Kim Kyeong Il , Hong Sung Jei , Hong Tae Whan
Published: June 2012

Nowadays, rapidly growing mobile machines such as tablet PC and smart phone equipped with touch screen panel using a sturdy material for products surface protection. Therefore, surge of chemical strengthening glass was increased. Through large areas of chemical strengthening glass, the surface scratch will cause a major failure. Most of these failures will be discarded because it is difficult to reuse. Thus, discarded chemical strengthening glass is expected to increase as with the demand. Accordingly, the importance of environmental pollution, waste landfill has been proposed. Recently, touch screen of chemical strengthened glass all-in-one type was commercialized. Therefore reuse is possible, due to surface of discarded chemical strengthening glass is washed and wipe off the electrode. In this study, we carried out the MLCA(Material Life Cycle Assessment; MLCA) on a chemical strengthening glass by landfill scenario, reuse scenario and identified the key issues.
Preparation of Porous Poly(butylene succinate)(PBS)/Starch Blends for Absorption of Copper (II) Ions
Authors: Zhou Han , Luo Xue Gang , Lin Xiao Yan , Li Ji Wei , Zhang Hong Ping
Published: June 2012

The porous composite adsorbent was prepared using directly the glycerol-plasticized poly (butylene succinate)(PBS) and corn starch that were melt blended by a twin screw extruder. The effect of different ratio of PBS to starch on volume stabilization of the composite adsorbent in the water was investigated, and the optimum mixing ratio was 100:25. The starch/PBS particles were treated by α-amylse on the condition of pH 5, the temperature 50. The major objective of this paper is to characterize the morphology in biodegradable PBS/starch blends using scanning electron microscopy. The effect of the dose of enzyme and hydrolysis time on removal efficiency of the composite adsorbent was studied. The results showed that the enzyme-treated starch/PBS particles had good adsorption efficiency for copper () ions compared to the starch/PBS particles. The optimum ratio of the starch to PBS was 100:25 and enzyme treatment condition was 2% (w/w) enzyme dosage (based on dry starch) and 8h hydrolysis time. Therefore the porous composite particles could be used as potential environmentally friendly materials.
The Study of Environmental Degradation Dharacteristics of Photodegradable Polyethylene Film
Authors: Shi Quan Bin , Luo Xue Gang , Lin Xiao Yan , Zhang Hong Ping
Published: June 2012

Photodegradable polyethylene films have attracted considerable interests in recently years for its environmental degradability. However, it would be a scientifically and technological challenging issue to assess the degradable process. In order to explore the effect of the photo sensitizer on natural environment degradation characteristics of photodegradable polyethylene film, we investigated the changes of the tensile strength and elongation at break of the PE film (as the control group) and the PE photodegradable film along with the time in the ambient conditions. Photodegradable PE films showed the greater decrement of the tensile strength and elongation at break than that of the control group after 90 days explosion in ambient conditions which indicated its excellent degradability. Thus, the photo sensitizer being used in the PE films could improve the degradability of the PE films in the ambient conditions to a great extent.
Current Induced Spin Injection in Si-MOSFET
Authors: Shlimak I. , Butenko A. , Golosov D.I. , Friedland K.J. , Kravchenko S.V.
Published: June 2012

Longitudinal resistivity in strong parallel magnetic fields up to B = 14 Tesla was measured in Si-MOSFET with a narrow slot (90nm) in the upper metallic gate that allows to apply different gate voltage across the slot and, therefore, to control the electron density n1 and n2 in two parts of the sample independently. The experimental scheme allows us to pass through the source-drain channel relatively large DC current (IDC), while the dynamic resistance was measured using a standard lock-in technique with small AC current. It was shown that the sample resistance is asymmetric with respect to the direction of DC current. The asymmetry increases with increase of magnetic field, DC current, and difference between n1 and n2. Results are interpreted in terms of a current-induced spin accumulation or depletion near the slot, as described by a spin drift-diffusion equation. The effect on the sample resistance is due to the positive magnetoresistance of Si-MOSFETs in parallel magnetic fields.
Magnetoresitive Properties of Gd/Ti Multilayers
Authors: Svalov Andrey V. , Vas’kovskiy V.O. , Barandiarán J.M. , Orue I. , Sorokin A.N. , Kurlyandskaya G.V.
Published: June 2012

Magnetization and magnetoresistance (MR) studies were carried out on the [Gd/Tnmultilayers with different thickness of Gd and Ti layers prepared by magnetron sputtering. The temperature interval of measurements was from 2 to 300 K, for the highest available magnetic field value of 100 kOe. A negative magnetoresistance was observed in all samples. The observed negative MR was analysed by using different magnetoresistance models.
Electronic and Spin Structure of Metal Phthalocyanines
Authors: Tikhonov E.V. , Khokhlov D.R. , Uspenski Y.A. , Kulatov E.T. , Belogorokhov I.A.
Published: June 2012

We present the first-principles calculations of MPc molecules having the magnetic moment. Some of these molecules contain the magnetic 3d-metal atom (MnPc, FePc, and CoPc), whereas others have the non-magnetic metal atom with an odd number of electrons (CuPc, AgPc, and GaPc). Calculations show that the density functional theory greatly decreases the HOMO-LUMO gap and the spin-splitting energy, comparing with hybrid functional results closely related to the many-electron theory. It is found that the HOMO-LUMO gap of MPc molecules shows moderate changes, while their spin-splitting energy is very sensitive to the localization of spin density and varies very significantly.
Atomic Force Microscopy Measurements of Magnetostriction of Soft-Magnetic Films
Authors: Harin E.V. , Sheftel’ E.N. , Krikunov A.I.
Published: June 2012

A method for direct measuring the magnetostriction of ferromagnetic films (deposited on nonmagnetic substrates) in using an atomic force microscope was suggested. In measuring the magnetostriction for films 10 [mm] in length and 0,2 [μm] in thickness, which were deposited on substrates 200 [μm] thick, the minimum measured magnetostriction magnitude is ~10-7. The procedure was tested for Ni and Fe films. The magnetostriction magnitudes measured for the films are comparable with those obtained by other magnetostriction-measuring methods. The effect of alloying with zirconium and nitrogen on the magnetostriction of nanocrystalline Fe films was studied.
Effect of Milling in Various Media and Annealing on the Structure and Magnetic Properties of Strontium Hexaferrite Powder
Authors: Ketov S.V. , Lopatina E.A. , Bulatov T.A. , Yagodkin Yu.D. , Menushenkov V.P.
Published: June 2012

In the present work, the structure and magnetic properties of strontium hexaferrite powder during milling in various media and subsequent annealing were studied. The milling of the powder leads to an abrupt decrease in the powder particle size and the average crystallite sizes as well as an increase in lattice microstrains of the SrFe12O19 phase. During milling in toluene, no changes in the phase composition were observed, whereas, during milling in water, the Fe2O3 phase (type H1.1) is formed. In the powder milled in oleic-acid-containing toluene a small quantity of α-Fe was found. After milling, the saturation magnetization and remanence decrease; at the same time, the coercive force of the powder milled in toluene is unchanged with increasing milling time, but slightly increases after milling in water and in oleic-acid-containing toluene. The annealing allowed us to increase the magnetic properties of the powder. It is conditioned by formation of nanocrystalline state. Moreover, the magnetic properties values depend on the medium and time of milling. The annealed powders are characterized by the following magnetic properties: μ0Нci = 0.42 ÷ 0.49 T, Br = 0.23 ÷ 0.24 T, (BH)max = 8-9.6 kJ/m3.
Magnetic Properties of Nanostructured Co-Based Alloys Produced by Dynamic Compaction and Plasma Spray Deposition
Authors: Kuzovnikova L. , Denisova Elena  A. , Kuzovnikov A. , Iskhakov Rauf S. , Lepeshev A.
Published: June 2012

The bulk nanostructured Co-P alloys were prepared by dynamic compaction and a plasma spray deposition techniques. The magnetic characteristics, such as the saturation magnetization, M0, the Bloch constant, B, the local magnetic anisotropy field, Ha, the ferromagnetic resonance linewidth, ΔH, the coercivity, Hc, were investigated. A comparison between the magnetic properties of the Co-P alloys prepared by dynamic compaction and a plasma spray deposition techniques was carried out.
Local Electronic and Crystal Structure of Rare-Earth Cobalt Phosphides RCo2P2 Studied by XAFS Spectroscopy
Authors: Menushenkov Alexey P. , Yaroslavtsev Alexander A. , Grishina Olga V. , Chernikov Roman V. , Arico Alexandra A. , Thompson Corey M. , Kovnir Kirill , Shatruk Michael
Published: June 2012

Abstract. The valence state of Ce and Eu was investigated by X-ray absorption near-edge structure (XANES) spectroscopy above L3-Ce and L3-Eu absorption edges in series of RCo2P2 (R = La, Ce, Pr, Eu) magnetic intermetallics. At the same time under similar conditions the rearrangement of Co and Pr local environment vs. temperature was studied by extended X-ray absorption ¯ne structure (EXAFS) spectroscopy above K-Co and L3-Pr absorption edges.
Effect of Heat Treatment on the Microstructure and Magnetic Properties of As-Cast SmCo5-Based Alloys
Authors: Menushenkov Vladimir P. , Sviridova T.A. , Shelekhov E.V. , Belova L.M. , Menushenkov Alexey P. , Chernikov R.V. , Sidorov V.V. , Grishina Olga V.
Published: June 2012

Local and crystalline structures of as-cast SmCo5±xalloys subjected to various heat treatments were studied using EXAFS, X-ray diffraction, and metallographic analyses. XRD and EXAFS analyses of SmCo5-xalloys show the evidence of the Sm-enrichment of the SmCo5phase. The behavior of the lattice parameters of SmCo5phase in Sm-rich alloys during aging between 1120°C and 700°C can be related to the phase transformation of SmCo5into SmCo5-xphases.
Physical and Magnetic Properties of Sm0.2Gd0.8Ni4B Compound
Authors: Özçelik Bekir , Kantarci Nilay , Nane Onur , Yakinci M. Eyyüphan
Published: June 2012

Physical properties of theSm0.2Gd0.8Ni4Bcompound have been investigated by means of theX-ray powder diffraction, DC and AC-susceptibility techniques. The compound studied crystallizes in CeCo4B type structure withP6/mmmspace group. The unit-cell parametersaand c are determined as 5.01 and 6.95 Å, respectively, and the unit-cell volumeVis calculated as 151.08 Å3. DC and AC magnetic measurements present the visible magnetic phase transition from paramagnetic to ferromagnetic, around definite transition temperature. The magnetic phase transition temperature of the compound is obtained from DC magnetization, AC-susceptibility and the well known Kouvel-Fisher method as 36.6, 35.7 and 35.2 K, respectively. The saturation magnetization (Ms) and the coercive fields (Hc) of the compound are found to be 3.7µB/f.u and 277 Oe, respectively, by using the hysteresis loops at 9.5 K. We have also investigated the non-linear AC-susceptibility of the compound, around its ferromagnetic transition temperature, as a function of temperature, frequency and amplitude of the AC-driving field. In order to explain the measured experimental results, we have used the theory developed for ferromagnetic, based upon the mean field model. The measurements exhibit both frequency and amplitude dependencies. Observed dependencies are compared with the existing theories of linear and nonlinear susceptibilities with reference to short- and long-range interactions. In Kouvel-Fisher method, one plots1/χ1*(dχ-1/dT)againstT,obtaining a straight line. The slope of this line gives the critical exponent γ,and it intersects theTaxis atTc.In order to obtaindχ-1/dTand the best straight line, we used a two-point numerical differentiation program and linear regression method, respectively. The critical exponent γ of the sample is calculated to be 2.78 ± 0.05. The value of the critical exponent β, which is characteristic of static phase transition to a ferromagnetic state, is estimated as 2.41±0.3 from the slope of the line obtained the plot of the absolute third-harmonic values versus the reduced temperature on a log–log scale.
Suppression of Spin-Glass State in PrB6
Authors: Anisimov M.A. , Bogach A.V. , Glushkov V.V. , Demishev S.V. , Samarin N.A. , Shitsevalova N.Y. , Levchenko A.V. , Filipov V.B. , Kuznetsov A.V. , Sluchanko N.E.
Published: June 2012

The comprehensive study of transverse magnetoresistance (MR) and magnetization has been carried out on the high quality single crystals of PrB6 in the wide range of temperatures 2-40K and magnetic fields up to 80kOe. In order to estimate the role of boron vacancies in the formation of the new spin-glass (SG) phase detected by Alekseev et al. below 20K the experiments were carried out on the ordinary (initial state) and annealed single crystals of PrB6. The data obtained demonstrate the appearance of spontaneous magnetization below TSG21.3K with M~1.6 emu/mol for initial state and the absence of spontaneous magnetization for the annealed PrB6 samples. On the contrary, quite similar behavior of MR was detected for various samples of PrB6. Our results suggest the existence of the aggregated boron vacancies which provoke the new SG phase formation in PrB6 at TSG.
High Pressure Synthesis and Magnetic Properties of Cubic B20 MnGe and CoGe
Authors: Tsvyashchenko A.V. , Sidorov V.A. , Fomicheva L.N. , Krasnorussky V.N. , Sadykov R.A. , Thompson J.D. , Gofryk K. , Ronning F. , Ivanov V.Y.
Published: June 2012

Samples of MnGe and CoGe having cubic B20 structure were prepared at high pressure. Magnetic measurements showed that CoGe is a Pauli paramagnet, but MnGe exhibits antiferromagnetic-type ordering below TN = 175 K. The magnetic susceptibility of MnGe follows a Curie-Weiss law above 300 K with an effective magnetic moment µeff = 3.68 µB/f.u. and θp = + 231 K. The large positive value of θp indicates a strong ferromagnetic exchange. The value of the effective moment is close to the free Mn4+ ion (4F3/2) value 3.87 µB/f.u. From measurements of the magnetization of MnGe in fields up to 60 kOe and in the temperature range 2-350 K, we constructed its T-H magnetic phase diagram which is similar to that proposed for MnSi-type compounds with helical magnetic order. Specific heat measurements reveal that the total magnetic entropy of MnGe relative to nonmagnetic CoGe is equal to 3.55 J/mole-K (0.62Rln2).
Field-Theory Description of Nonequilibrium Critical Dynamics for Spin Systems
Authors: Kalashnikov Ivan A. , Prudnikov Pavel V.
Published: June 2012

Renormalization-group approach is applied to investigate the short-time nonequilibriumcritical behavior of pure and diluted spin systems with nonmagnetic point-like impurities.The dissipative relaxation dynamics with non-conserved order parameter is considered. For thefirst time the description of the order parameter growth induced by the initial nonequilibriumstate of system is carried out at fixed dimension d = 3 without use of ε-expansion.
Structure and Magnetic Properties of Nanocrystalline Fe-Cr-Co Alloys for Permanent Magnets
Authors: Ushakova Olga , Malinina Raisa
Published: June 2012

The magnetic properties of alloy containing Fe and 30%Cr, 15 % Co with addition of 3 % Mo after cold rolling were analyzed. It was shown that Hc of Fe-Cr-Co-Mo alloys with cubic texture of recrystallization increases up to 30 %: Hc = 76 kA/m. It was concluded that additional reserves of magnetic properties are created with a more perfect crystallographic and magnetic texture during the recrystallization process.
Structure and Magnetic Properties of Hard Magnetic Nanocrystalline Oxide-Based Alloys
Authors: Menushenkov Vladimir P. , Savchenko A.G. , Yagodkin Yurii D.
Published: June 2012

The structure and properties of SrFe12O19 powders, which were produced by mechanical activation followed by annealing and had a nanocrystalline structure, were studied. The powders prepared exhibit a high coercive force μ0Hci=0.40-0.45 Т. The substantially higher coercive force (up to 0.75-0.82 T) was typical to SrFe12O19 powders produced by oxide-glass crystallization. Nanostructured materials comprising Fe3O4 and Fe phases with crystallite sizes of 10-30 nm are shown can be prepared from Fe2O3+Fe, Fe2O3+Fe+Co and FeO+Co powder mixtures by mechanochemical technique followed by annealing. These nanomaterials have the hard magnetic properties and their coercive force reaches μ0Hci 0. 08 T.
Magnetic Properties of Nd0.6Dy0.4Fe3(Bo3)4
Authors: Demidov A.A. , Gudim I.A. , Eremin E.V.
Published: June 2012

The magnetic properties of trigonal Nd0.6Dy0.4Fe3(BO3)4 substituted compound with the competitive Nd-Fe and Dy-Fe exchange interactions have been investigated. It has been shown that in Nd0.6Dy0.4Fe3(BO3)4 a spontaneous spin-reorientation transition from an ease-axis state to an easy-plane occurs near 31 K. Anomalies of the magnetization curves are observed in a spin-flop transition induced by the magnetic field B||c. The calculations were performed using a molecular-field approximation and a crystal-field model for the rare-earth subsystem. Extensive experimental data on the magnetic properties of Nd0.6Dy0.4Fe3(BO3)4 have been interpreted and good agreement between theory and experiment has been achieved using the obtained theoretical dependences.
Pressure Induced AF - F - AF Magnetic Phase Transformations in Pd Substituted FeRh Compound
Authors: Chirkova A.M. , Volegov A.S. , Neznakhin D.S. , Stepanova E.A. , Baranov N.V.
Published: June 2012

At ambient pressure, the Fe0.49(Rh1-xPdx)0.51 alloys with the Pd concentration within 0 < x < 0.12 exhibit an antiferromagnetic (AF) state below the critical temperature Tt, while above x = 0.12 the alloys have a ferromagnetic (F) order up to the Curie temperature TC 650 K. The temperature and field dependences of the magnetization in the alloys with x = 0.08; 0.13 were investigated under hydrostatic pressure up to 10 kbar. The application of pressure of about 8.5 kbar is observed to induce the F-AF phase transition in the ferromagnetically ordered compound with x = 0.13. The AF-F-AF phase evolution was revealed with increasing pressure in the AF-ordered alloy with x = 0.08.
Ageing Phenomena in Two-Dimensional XY-Model
Authors: Alekseyev S.V. , Prudnikov Pavel V. , Prudnikov Vladimir V.
Published: June 2012

The ageing phenomena in two-dimensional XY model at the low temperatures are investigated by Monte-Carlo method. The two-time correlation function and dynamic susceptibility are measured. Violations of the fluctuation-dissipation theorem are investigated.
Non-Equilibrium Critical Dynamics of Ferromagnets with Long Range Correlated Defects
Authors: Kulikov Dmitry N. , Prudnikov Pavel V.
Published: June 2012

The simultaneous eﬀect of non-equilibrium initial states and correlation betweendefects of the structure on the evolution of anisotropic disordered systems at the critical pointwas analyzed. The ﬁeld theory description of the non-equilibrium critical behavior of three-dimensional disordered systems with the long-range correlated defects was given and the dy-namical critical exponent of the short-time evolution was calculated in the two-loop approxima-tion without the use of the "-expansion. The values of the dynamical critical exponent obtainedby using various methods for summing asymptotic series were compared with the results ofthe computer simulation of the non-equilibrium critical behavior of the three-dimensional dis-ordered Ising model in the short-time regime.
Theoretical Study of Twin Boundary Motion in Heusler Ni-Mn-Ga Alloys Using Monte Carlo Method
Authors: Kostromitin K.I. , Buchelnikov Vasiliy D. , Sokolovskiy V.V. , Entel P.
Published: June 2012

The twin boundary motion in Ni-Mn-Ga Heusler alloys has been investigated using Monte Carlo simulations. The Hamiltonian of system includes magnetic and elastic parts and two magnetoelastic terms. It is shown that the twin boundary shifts in a magnetic field at the constant temperature. The spin and strain volume fractions have been obtained at different temperatures.
Magnetocaloric Effect in RСo2 Compounds
Authors: Ovchenkova I.A. , Tskhadadze G.A. , Zhukova D.A. , Ivanova T.I. , Nikitin S.A.
Published: June 2012

The direct measurements of the magnetocaloric effect (MCE) and the magnetization have been conducted for a large number of compounds based on RCo2(R = Tb, Ho) with substitutions by nonmagnetic elements (Y, Al, Ga) in rare earth and 3d- sublattices. The concentration dependencies of the Curie temperature and the value of MCE are discussed. The linear dependencies of the value of the MCE from the second power of the magnetization were find out at the region of the phase transition of the second type .
Ab Initio Calculation of the System Cr–GaSb: A New High-Pressure Phase Containing Defects
Authors: Magnitskaya M.V. , Kulatov E.T. , Titov A.A. , Uspenskii Y.A. , Maksimov E.G. , Popova S.V. , Brazhkin V.V.
Published: June 2012

We report on ab initio density-functional calculations of a novel spintronics-related compound CrGa2Sb2 recently synthesized under high pressure. The effect of Cr deficiency on the electronic, magnetic and optical properties of CrGa2Sb2 is considered. New X-ray structural measurements up to high pressure of 9 GPa are presented.
Magnetic Properties and Magnetocaloric Effect of Gd3Ni in Crystalline and Amorphous States
Authors: Shishkin D.A. , Baranov N.V. , Proshkin A.V. , Andreev S.V. , Volegov A.S.
Published: June 2012

The liquid quenched Gd3Ni alloy is observed to exhibit a ferromagnetic behavior below TC = 117 K unlike crystalline compound having an antiferromagnetic order at T < TN = 99 K. Rapid quenching from the melt results in a considerable enhancement of the magnetocaloric effect in Gd3Ni at low magnetic fields. The maximal value of the isothermal magnetic entropy change at a magnetic field change of 20 kOe for the amorphous Gd3Ni surpasses by more than 8 times the SM value for the polycrystalline counterpart. The relative cooling power for the amorphous Gd3Ni alloy is estimated as 265 J kg-1 and 676 J kg-1 at a magnetic field change of 20 kOe and 50 kOe, respectively.
Experimental Study of the Faraday Effect in 1D-Photonic Crystal in Millimeter Waveband
Authors: Girich A.A. , Polevoy S.Y. , Tarapov Sergey I. , Merzlikin A.M. , Granovsky A.B. , Belozorov D.P.
Published: June 2012

The paper is devoted to experimental study of Faraday Effect enhancement. The experimental structure consists of photonic crystal, loaded with ferrite, which in turn is covered by thin metal layer or wire medium. An analysis of the transmission/reflection spectra for both unloaded and loaded photonic crystals shows that the surface oscillation mode (the surface state) is formed in the crystal band gap. A good agreement exists between experimental data and numerical calculations.
Proximity Effect for Asymmetrical Three-Layered FS Structures in External Magnetic Field
Authors: Avdeev Maxim , Proshin Yurii N. , Khusainov Mansur G. , Tsarevskii Sergey
Published: June 2012

We study asymmetrical three-layers F1F2S and F1SF2 structures in an external parallelmag-netic field. Assuming that all F and S layers are dirty, we solve the boundary value problem for theUsadel function. We calculate the critical temperature of in the F1F2S and F1SF2 systems as functionof the F layers thicknesses and external magnetic field.
Non-Equilibrium Critical Relaxation of Heisenberg Ferromagnets with Long-Range Correlated Defects
Authors: Medvedeva M. , Prudnikov Pavel V.
Published: June 2012

The dynamic critical behavior of the three-dimensional Heisenberg model with longrangecorrelated disorder was studied by using short-time Monte Carlo simulations at criticality.The static and dynamic critical exponents are determined. The simulation was performed fromordered initial state. The obtained values of the exponents are in a good agreement with resultsof the field-theoretic description of the critical behavior of this model in the two-loopapproximation.
DC Magnetic Susceptibility of CeCoGe2.36Si0.64 under High Pressure
Authors: Larrea J.J. , Teyssier J. , Ronnow H. , Müller M. , Sidorenko A. , Paschen S.
Published: June 2012

We report an investigation of the magnetic phase diagram of the heavy fermion com-pound CeCoGe2.36Si0.64 using DC magnetic susceptibility measurements under high pressure upto 10 kbar. The antiferromagnetic order that develops at ambient pressure below about 5.5 Kremains essentially unaﬀected by pressure in the investigated pressure range up to 10 kbar. Onthe other hand, moderate magnetic ﬁelds appear to induce a quantum critical point in a sam-ple subject to a pressure of 2 kbar. We discuss the role of disorder in the series of compoundsCeCoGe3−xSix.
The Josephson Current in the SFS Sandwich Taking into Account the Proximity Effect and Umklapp Processes
Authors: Tumanov Vadim A. , Proshin Yurii N.
Published: June 2012

We consider the Josephson effect in a three-layer symmetric superconductor-ferromagnet-superconductor (SFS) system. In the framework of the proximity effect theory we calculate the Josephson current as a function of the ferromagnet thickness, taking into account the Umklapp processes at the internal boundary and the critical temperature dependence of the order parameter phase difference. The results of the calculations are in good agreement with experimental data.
On the Superconductivity of High-Spin Transition Metal Compounds
Authors: Zaitsev R.O.
Published: June 2012

The possibility of the Cooper instability in transition metal compounds has been established on the bases of an idea about a strong interaction in a unit cell. The phase diagram of the superconducting ordering depending on a number of holes (hd) of the 3d-shells has been obtained. The non-phonon BCS constant has been calculated.
Local Moments in the Dynamic Spin-Fluctuation Theory of Metallic Magnetism
Authors: Melnikov N.B. , Reser B.I. , Grebennikov Vladimir I.
Published: June 2012

In the dynamic spin-fluctuation theory extended by taking into account higher-order terms of the free energy and uniform fluctuations along with the local ones, simple computational formulae for local magnetic moment are obtained. The temperature dependence of local magnetic moment in the Fe0.65Ni0.35 Invar is calculated. Good agreement with the experimentally estimated value of the magnetic volume change is achieved.
Magnetism and Magnetoresistance in NiFe/Bi/NiFe Films
Authors: Patrin K. G. , Yakovchuk V. Y. , Patrin G.S. , Yarikov S. A.
Published: June 2012

Interlayer interactions in FeNi/Bi/FeNi trilayers have been experimentally studied. Based on the data of SQUID magnetometry and magnetic resonance investigations, it is shown that the interlayer interaction is determined by a bismuth spacer thickness and temperature. The giant magnetoresistive effect in the trilayer films has been discovered.
Ferromagnetic-Like Behavior of Pt Nanoparticles
Authors: Antipov S. D. , Gorunov G. E. , Perov N. S. , Pivkina M. N. , Said-Galiyev E. E. , Semisalova A.S. , Stetsenko P. N.
Published: June 2012

The magnetic properties of small 4d, 5d metal nanoparticles of Pd, Pt (clusters) are attracting a great attention because these materials in bulk are paramagnetic. In this work we report the ferromagnetic-like behavior of the small Pt nanoparticles prepared by chemical method. Highly dispersed Pt clusters have been synthesized on the surfaces of a porous spherical γ-Al2O3 particles. The process of the chemical deposition of metalorganic fluid with employment of the supercritical fluid was used. The samples of the Pt/γ-Al2O3 nanoparticles have been prepared in INEOS RAS. The nanoparticles size distribution was determined by small-angle X-rays scattering (SAXS). It was found that the Pt clusters have a bimodal particle size distribution with two peaks: R1max=20 Å and R2max=40 Å. The magnetic properties of the clusters have been investigated, using VSM magnetometer, in magnetic field up to ±3 kOe and at a temperature range from 80 to 400 K. It was observed that Pt/γ-Al2O3 nanoparticles show the ferromagnetic-like behavior in whole specified temperature range, the value of coercivity decreases gradually from 130 Oe to 80 Oe. The origin of ferromagnetic-like behavior of the Pt/γ-Al2O3 nanoparticles is discussed.
Peculiarity of the Ferromagnetic and Spin-Wave Resonance in Exchange-Coupled NiFe/X/NiFe Three Layer Structures (X=Ag, Cu, DyCo)
Authors: Iskhakov Rauf S. , Stolyar S.V. , Yakovchuk V. Y. , Chizhik M. V.
Published: June 2012

FMR and SWR spectra of exchange-coupled structures NiFe/Cu/NiFe, NiFe/Ag/NiFe and NiFe/DyCo/NiFe have been investigated. We revealed that the optical satellites of the exchange spin-wave modes are characterized not by the standard Kittle-dependence but by their own resonance field dependence on the mode number: Hropt(n) ~ n5/2.
Magnetic Properties of CoFeB-SiO2 Nanocomposite and [(Co40Fe40B20)X(SiO2)100-X /α-Si:H]n Multilayer Films
Authors: Denisova Elena  A. , Iskhakov Rauf S. , Chekanova Lidia , Kalinin Yuri , Sitnikov Alexander
Published: June 2012

Magnetic properties of (Co40Fe40B20)X(SiO2)100-X nanogranular composite films, [(Co40Fe40B20)X(SiO2)100-X /a-Si:n multilayer films and layered (Co40Fe40B20)X(SiO2)100-X films with X ranging from 30 to 80 have been characterized by means of magnetic measurements and ferromagnetic resonance. Layer thickness was varied between 1.3 and 6 nm. Thermal decrease of (Co40Fe40B20)X(SiO2)100-X composite magnetization follows the T3/2 law. The spectrum of standing spin-wave has been detected in the perpendicular experiment configuration for films with the metal phase content above 48 vol. %. It is found that the Hr(n2) dependencies are non-linear. Such behavior is probably caused by the fluctuations of magnetic parameters (the magnetization and the ferromagnetic exchange coupling) in nanocomposite films. A comparison between the magnetic properties of (Co40Fe40B20)X(SiO2)100-X granular films and [(Co40Fe40B20)X(SiO2)100-X /a-Si:n multilayer films was carried out.
Ferromagnetic Co-P Powders with Nanodiamond and Corundum Precipitates
Authors: Goncharova O.A. , Chekanova L.A. , Denisova E.A. , Komogortsev S.V. , Iskhakov Rauf S. , Eremin E.V.
Published: June 2012

Powders of Ñî-Ð alloy with ultradispersed corundum (Al2O3) and detonation nanodiamond (DND) precipitates were synthesized by chemical reduction. The products were characterized by X-ray diffraction and scanning electronic microscopy. The shape of the particles was spherical and they were ferromagnetic. Magnetization dependence on field in applied fields of up to 40 kOe and magnetization dependence on temperature in the temperature range from 2 to 300 K were measured. Influence of precipitates on magnetic properties was studied.
Arrangement of Fe/Cr/Fe Film Magnetisation Curve outside the Hysteresis Loop as the Manifestation of Spin Density Wave in Cr Layer
Authors: Gudin S.A. , Kurkin M.I. , Gapontsev A.V.
Published: June 2012

Conditions of coexistence of Fe/Cr/Fe film states with parallel and antiparallel Fe layer magnetisations orientation are established. The transition from antiparallel to parallel orientation in external magnetic field is caused with Cr layer spin density wave phase change when wave node in the centre of Cr layer is substituted with wave antinode. The coexistence of these two states means that Fe/Cr/Fe film ferromagnetic state created with external magnetic field retains after the switching this field off. This phenomenon will manifest itself in the fact that magnetisation curve of initially antiferromagnetic Fe/Cr/Fe film will go outside the hysteresis loop of it's remagnetisation in ferromagnetic state created by external field.
Properties of Single Molecule Magnet Ni4Mo12
Authors: Kostyuchenko Victor V.
Published: June 2012

At the present time two models can more or less describe the magnetic properties ofNi4Mo12. The rst one is based on the assumption of essential role of non-Heisenberg exchangeinteractions. The key feature of the second model is the symmetry breaking of exchange inter-actions. The present work is focused on the forecasting power of these spin models. Mechanismresponsible for non-Heisenberg exchange interactions is the same as mechanism resulting in in-teraction of spin chirality with external magnetic eld. An additional level splitting in magnetic eld can be observed in this case. The symmetry breaking of exchange interactions inevitablyleads to nonzero toroidal moment and related to it magnetoelectric phenomena.
Spin Ordering on the Surface of a Topological Insulator with Magnetic Ions
Authors: Men'shov V.N. , Tugushev V.V. , Chulkov E.V.
Published: June 2012

We study the effect of magnetic doping on appearance of ferromagnetic (FM) order on the surface of a three-dimensional topological insulator. Assuming the exchange coupling of the Dirac fermions with the dilute magnetic ions, we find that the system under consideration is unstable with respect to a spontaneous uniform magnetization along the out-of-plane direction. The appearance of the magnetization is accompanied by opening of a gap in the spectrum of surface states. In the framework of a mean-field approach, we analyze the possibility of the FM order on the magnetically doped surface of topological insulator at different temperatures and positions of the chemical potential.
Electron Transport in Partially Filled Iron Carbon Nanotubes
Authors: Migunov Vadim , Li Zi An , Spasova Marina , Farle Michael
Published: June 2012

We report electron transport properties of iron filled multiwalled carbon nanotubes (MWCNT) with outer diameters of 30 to 80 nm and lengths of 1 to 10 μm. Our study is combined with a structural investigation of the iron core using transmission electron microscopy (TEM) and electron energy loss spectroscopy (EELS). It was found that high current densities of 1.8x107 A/cm2 increase the conductivity of the MWCNT by a factor of two at 300 K, while the Fe core disappears probably forming defect states in the carbon shells. The enhanced diffusion of iron is most probably the result of local heating of the iron followed by implantation of iron atoms in the nanotube layers.
Spin and Elastic Waves with the Random Coupling Parameter
Authors: Ignatchenko V.A. , Polukhin D.S.
Published: June 2012

Dynamic susceptibilities (Greens function) in a system of two wave fields of different physical nature connected by the zero-mean random coupling parameter are studied. Magnetoelastic waves in zero-mean magnetostrictive media are considered. It is shown that the Greens functions of the spin and elastic waves at the intersection of the initial dispersion laws have the form of broad single-mode peaks with the fine structure on the tops of these peaks: the narrow resonance on the top of and the narrow antiresonance on the top of . For the long-wave inhomogeneities the widths of the broad peaks and narrow peaks are determined by the root-mean-square fluctuation and the correlation wave number, respectively.
Carbon Nanotube Bolometer: Transport Properties and Noise Characteristics
Authors: Rod Irina , Wirtz Christian , Kazakova Olga , Panchal Vishal , Cox David , Zähres Horst , Posth Oliver , Lindner Jürgen , Meckenstock Ralf , Farle Michael
Published: June 2012

The temperature dependent resistance and the noise characteristics of an individual multi-wall carbon nanotube (CNT) decorated with a finite number of magnetic nanocubes are investigated. We show that CNT is a highly sensitive bolometer and can enable measurements of magnetic resonance in a single nanoparticle.
Domain Structure Reversible Reconstruction and Changing of Domains Width in Ferrite-Garnet Films Caused by Water Molecules Adsorption
Authors: Zubov V.E. , Kudakov A.D. , Levsнin N.L. , Gusev M.Yu. , Neustroev N.S.
Published: June 2012

Due to water molecules adsorption the reversible change of domains width and domain structure reconstruction in bismuth-doped ferrite-garnet thin films with perpendicular magnetic anisotropy was observed. The change of domains width was 15% in saturated water vapor at room temperature. The decrease of domains width is explained by the reduction of effective perpendicular magnetic anisotropy constant due to water molecules adsorption.
2F5/2 Manifold Splitting of Ce3+ in PbCeX (X= Te, Se, S): A Magnetic Susceptibility Study
Authors: Gratens X. , Isber Samih , Charar S. , Golacki Z.
Published: June 2012

The magnetic susceptibility of Pb1-xCexX (X = S, Se and Te) crystals with several Cerium concentrations ranging from x = 0.006 to 0.036 has been measured between 2 K and 300 K. The experimental susceptibility curves were found to be consistent with a 2F5/2 lowest manifold for Ce3+ ions; the cubic crystal-field splitting values of 2F5/2 were estimated to be about 340 K, 440 K and 540 K for Pb1-xCexTe, Pb1-xCexSe, and Pb1-xCexS, respectively. For all the studied samples, it was found that the 7 doublet lies below the 8 quadruplet. These results confirm that Ce3+ ions substitute Pb2+ in the host crystals. Furthermore, the effective Landé factors were determined by X-band (~9.5 GHz) Electron Paramagnetic Measurements (EPR) to be g = 1.333, 1.364, and 1.402 for Ce ions in PbX, X = S, Se, and Te, respectively.
Influence of Magnetic Impurities on Thermoelectric Capabilities of Bi2Te3, Sb2Te3, and Bi2Se3
Authors: Kulbachinskii V.A. , Kytin V.G. , Kudryashov A.A. , Tarasov P.M.
Published: June 2012

Temperature dependencies of the Seebeck coefficient, electrical conductivity, heat conductivity and the dimensionless thermoelectric figure of merit ZT ofp-Bi2Te3,n-Bi2Se3and Sb2Te3doped by Fe or Cr have been investigated in the temperature interval 7 <T< 300 K. At T=4.2 K the Shubnikov-de Haas and Hall effects have been measured.By increasing the Fe content, the hole concentration decreases inp-Bi2-xFexTe3, while the electron concentration increases inn-Bi2-xFexSe3.The hole concentration decreases in Sb2-xCrxTe3with Cr doping. This demonstrates that Fe or Cr act as donors. The Seebeck coefficient increases inp-Bi2-xFexTe3and Sb2-xCrxTe3with increasing Fe or Cr content, while it decreases inn-Bi2-xFexSe3.
Amplification of even Harmonics in Nonlinear Magnetoimpedance Response of Amorphous Wires in Presence of Longitudinal Alternating Magnetic Field
Authors: Buznikov N.A. , Antonov A.S. , Rakhmanov A.A.
Published: June 2012

A model to describe the influence of longitudinal alternating magnetic field on the nonli-near magnetoimpedance in amorphous wires is proposed. The appearance of even harmonics in the voltage response is shown to arise from the asymmetry in the magnetization reversal process in the wire due to the presence of the longitudinal alternating field. The behavior of even harmonics is analyzed as a function of the external field, alternating field amplitude and current amplitude.
On Chiral Model of Graphene
Authors: Rybakov Yu.P.
Published: June 2012

The hybridized sp-states of valence electrons in the carbon atom can be describedby SU(2) matrix considered as the order parameter. The chiral model of graphene based onthis order parameter is suggested in the long-wave approximation, the ideal graphene planebeing determined by the kink-like solution. Corrugation of the graphene surface is describedin the form of ripple and rings. The approximate solution corresponding to an inﬁnite carbonnanotube is found.
Low Temperature FMR in the System of Non-Interacting Magnetic Nanodisks
Authors: Nedukh Sergey V. , Tarapov Sergey I. , Belozorov Dmytriy P. , Kharchenko Anna A. , Salyuk Olga Yu. , Kakazei Gleb N.
Published: June 2012

Magnetodynamical properties of systems of magnetic nanodisks at the microwave range and low temperatures were studied experimentally. Several periodic square arrays of Permalloy nanodisks deposited onto a glass substrate have been studied. The interdisk center-to-center distance in each array was equal to double disk diameter . The magnetoresonance studies were performed at 70-80 GHz frequency band and at the temperature of 4.2 K. The static external magnetic field was applied perpendicularly to the disks array. As a result the magnetoresonance absorption spectra have been obtained, containing both fundamental mode and spin wave modes. A comparative analysis of the results is performed with the X-band results obtained at T = 300K.
Magnetoimpedance of FeNi Thin Film Meanders
Authors: Volchkov Stanislav O. , Yuvchenko A.A. , Lepalovskij V.N. , Fernandez Eduardo , Kurlyandskaya G.V.
Published: June 2012

The role of the geometrical parameters was studied for thin film based [FeNi (100 nm)/Cu (3 nm)]4/FeNi (100 nm)/Cu (500 nm)/[FeNi (100 nm)/Cu (3 nm)]4/FeNi (100 nm) magnetoimpedance elements with open magnetic flux prepared by lithography technique. The maximum magnetoimpedance sensitivity of 17 %/Oe was obtained for meander shaped sample, exceeding the value of the maximum sensitivity of 5 %/Oe of the single stripe sample. The highest values of the magnetoimpedance were observed for relatively low frequency of order of 50 MHz convenient for technological applications. Both developed technology and obtained results can be useful for optimization of the design of miniaturized detectors of small magnetic field.
Microstructure of Bidisperse Ferrofluids in a Monolayer
Authors: Dobroserdova A. , Minina E. , Cerdà J.J. , Holm C. , Kantorovich S.
Published: June 2012

In the present study we briefly analyze the cluster structures observed in the model bidisperse ferrofluid constrained in quasi-2D (q2D) layer in the absence of an externally applied magnetic field. We use a combination of a DFT approach and molecular dynamic simulation to quantitatively describe various chain and ring structures and their equilibrium area fractions. We also show that to reach a good agreement between simulation data and theoretical predictions in q2D geometry in theory one needs to allow for more possible chain configurations than in the bulk system. We provide preliminary explanations why the microstructure of bulk bidisperse ferrofluids differs noticeably from the one in q2D layer.
Model of a Thin Rod with Viscoelastic Magnetizablematerial in the Alternating Magnetic Field
Authors: Zimmermann Klaus , Zeidis Igor , Naletova V.A. , Kalmykov S.A. , Turkov V.A.
Published: June 2012

The motion of a thin rod with viscoelastic magnetizable material in a channelunder the action of the alternating magnetic field of the coils is considered experimentally andtheoretically. The dynamic 2D model of a thin rod with viscoelastic magnetizable material isused. Numerical calculations of the rod motion in a vertical plane under the action of alternatingmagnetic field, gravity and friction are performed using this model. An influence of parametersof the problem on the rod velocity is studied theoretically. Theoretical results are comparedwith experimental data.
Magnetic Properties Variations in Iron Complexes with Benzimidazole Derivatives Depending on the System Spin State
Authors: Khenkin L.V. , Novakova Alla A. , Perov Nikolai S. , Vompe A. A.
Published: June 2012

Complexes of bivalent and trivalent iron with ligands based on benzimidazole derivatives have been synthesized and investigated. Chloride-ion was used as anion. Samples ligands differed from each other in the length of alkyl radical. Some samples were found in a mix-valence state, that complicated spin transition observation. Combination of Mossbauer spectroscopy and magnetic moment in high field (15kOe) measurements in the temperatures range 130K - 350K allowed us to establish the valence of iron ions under spin transition in our samples and spin transition temperature frameworks for these mix-valence compounds.