Template Synthesis,Structure, and Magnetic Properties of Layered Nanowires

Physics of the Solid State - Nanowires (NWs) consisting of Ni/Cu and Co/Cu alternating layers with a diameter of 100 nm and layer thicknesses varying between 10 and 500 nm are prepared by template...     

Synthesis and Magnetic Properties of Iron Polyhydrides at Megabar Pressures

JETP Letters - Iron polyhydrides have been synthesized at pressures of 77–157 GPa and temperatures up to 2000 K by the laser heating of an iron–borazane (ammonia borane NH3BH3) sample...     

The Electronic and Magnetic Properties of FCC Iron Clusters in FCC 4D Metals

The electronic and magnetic structures of small FCC iron clusters in FCC Rh, Pd and Ag were calculated using the discrete variational method as a function of cluster size and lattice relaxation. It was found that unrelaxed iron clusters, remain ferromagnetic as the cluster sizes increase, while for relaxed clusters antiferromagnetism develops as the size increases depending on the host metal. For iron in Rh the magnetic structure changes from ferromagnetic to antiferromagnetic for clusters as small as 13 Fe atoms, whereas for Fe in Ag antiferromagnetism is exhibited for clusters of 24 Fe atoms. On the hand, for Fe in Pd the transition from ferromagnetism to antiferromagnetism occurs for clusters as large as 42 Fe atoms. The difference in the magnetic trends of these Fe clusters is related to the electronic properties of the underlying metallic matrix. The local d densities of states, the magnetic moments and hyperfine parameters are calculated in the ferromagnetic and the antiferromagnetic regions. In addition, the average local moment in iron-palladium alloys is calculated and compared to experimental results.     

金属Ni纳米线阵列的制备及其磁性能

以Anopore为模板,用电化学沉积的方法制备了磁性金属镍的纳米线阵列.纳米线的直径约为200nm,长度约为50μm,长度直径比L/D达到250.此系统中相邻纳米线间存在着很强的耦合,所以易磁化方向垂直于纳米线的轴向. 关键词：     

Efficiency of Magnetooptical Conversion of Magnetic Fluxes Produced by the High-Temperature Superconductor Matrix

The possibility for using the ferrite-garnet magnetooptical films with a band domain structure has been considered with the aim of visualization of the spatial distribution of a magnetic flux near sensitive elements of a high-temperature superconductor matrix. The methods that enhance the efficiency of magnetooptical conversion have been suggested.     

Erratum to: Synthesis and Magnetic Properties of Iron Polyhydrides at Megabar Pressures

JETP Letters - An Erratum to this paper has been published: https://doi.org/10.1134/S0021364023330019     

单原子作为保护基团实现石墨双炔纳米线的表面合成

由于在贵金属表面的双炔单元具有高反应活性,表面合成半导体性质的石墨双炔纳米线通常会受到副反应的严重影响,难以分立的纳米线的高质量制备.本文利用化学气相沉积1,4-bis(4-bromophenyl)-1,3-butadiyne分子到表面发生Ullmann偶联反应,可实现无支链的石墨双炔纳米线[-C≡C-Ph_2-C≡C-]_n (PYP)的高产率合成.进一步的单化学键分辨的非接触原子力显微镜表征揭示了单个金增原子与双炔键之间形成了π-ligand键,有效地充当了反应过程中双炔单元的保护基团,避免了偶联过程中的副反应,从而实现了分立的超长石墨双炔纳米线的合成.这项研究将启发对在表面反应中各类表面增原子所起保护作用的更深入研究.     

Magnetic Structure of Diluted Iron Garnets

Physics of the Solid State - The report presents a model of the magnetic structure of diluted iron garnets with nonmagnetic ions in a dodecahedral sublattice. The dilution of magnetic iron...     

Optical Properties of Doped Nanowires in External Electric and Magnetic Fields

Optics and Spectroscopy - Impurity-induced absorption of light in quantum wires in the presence of external collinear electric and magnetic fields directed perpendicular to the nanowire axis is...     

Preparation and Properties of Iron and Iron Oxide Nanocrystals in MgO Matrix

We have prepared α-iron and magnetite (Fe₃O₄) nanoparticles in MgO matrix from a mixture of nanocrystalline Fe₂O₃ with Mg(H,O) powders calcinated in hydrogen. This procedure yielded spherical magnetic nanoparticles embedded in MgO. Transmission electron microscopy and Mössbauer spectroscopy were used for structure and phase analysis. The measurements of magnetic properties showed increased coercivity of the nanocomposite samples.     

Electrical and Magnetic Properties of FeSi2 Nanowires

We report the characterization of self-assembled epitaxially grown FeSi₂ nanowires (NWs) in terms of electrical and magnetic properties. NWs grown by reactive deposition epitaxy (RDE) on silicon (110) show dimensions of 10nm×5nm, and several micrometres in length. By using conductive-AFM (c-AFM), electron transport properties of one single NW is measured, resistivity of a single crystalline FeSi₂ NW is estimated to be 225μ\Ω ・cm. Using superconducting quantum interference device (SQUID), we measure a magnetic moment of 0.3±0.1 Bohr magneton per iron atom for these FeSi₂ NWs.     

Magnetic Properties of Iron Oxide Nanoparticles Obtained by Laser Evaporation

Russian Physics Journal - The paper concentrates on a synthesis of spherical magnetic particles obtained by laser evaporation under various process conditions. Depending on the process conditions,...     

Binary and Ternary Alloy Nanowires: Correlation of Structural and Magnetic Properties

Physics of the Solid State - Several types of nanowires from alloys of various compositions obtained by the method of matrix synthesis based on track membranes are investigated in this study....     

α-Fe2O3磁性微球的合成及磁性能

以氯化铁（FeCl3·6H2O）和氨水（NH3·H2O）为原料,以十六烷基三甲基溴化铵（CTAB）为表面活性剂,采用沉淀法制备了氧化铁磁性微球.所得样品用XRD、SEM及SQUID-VSM等手段进行了表征.结果表明,所得氧化铁磁性微球为斜方六面体结构,其粒径大小在0.5-1.5μm范围,其剩余磁感应强度为0.06emu/g,矫顽力为1700Oe,表现出一定的铁磁性.     

Magnetic Properties of Iron Clusters in Silver

Time differential perturbed γ-γ angular correlation technique was used to measure the magnetic hyperfine field (MHF) at Tb sites in the intermetallic compound Tb₃In₅ using the ¹⁴⁰La → ¹⁴⁰Ce nuclear probe. The measurements were carried out in the temperature range of 8 to 295 K. Two different temperature dependent magnetic frequencies were observed below 30 K, which were assigned as ¹⁴⁰Ce substituting the two inequivalent Tb sites in the orthorhombic structure of Tb₃In₅. The temperature dependence of MHF also shows a possible deviation from an expected Brillouin-like behavior for temperatures below 18 K. A Néel transition at 27 K was observed from magnetization measurements in the samples. The magnetization as a function of the applied magnetic field was measured at two temperatures, 5 and 40 K, and the results show antiferromagnetic and a typical paramagnetic behavior, respectively. In both cases it was not observed saturation under high magnetic field.     

Structure and Properties of Titanium Aluminum Alloy Produced by Friction Stir Welding

Russian Physics Journal - The paper deals with the fabrication of lap joints of titanium ОТ4-1 alloy and aluminum AlMg5 alloy sheets by means of friction stir welding (FSW). The X-ray...     

Effect of Crystalline Quality on Magnetic Properties of Mn-Doped ZnO Nanowires

The diluted magnetic semiconductor （DMS）, which exploits both the spin and the charge of car- riers, is one of the most important materials to re- alize semiconductor spintronies.Many research works have been focused on the magnetic properties of Mn-doped ZnO due to its room-temperature ferro- magnetism （RT-FM）, which is very important for commercial applications. Recently, Mn-doped ZnO nanostruetures were developed for the nano spintronic devices, and kinds of Mn-doped ZnO nanostrue- tures have been prepared with room-temperature fer- romagnetic behavior, while conflicting arguments produced no consensus on the origin of RT-FM in these systems. Vinod et al. reported that the RT-FM in 5 wt% Mn-doped ZnO nanorods is attributed to the increase in the specific area of grain boundaries and the interaction between Mn2＋ ions and Zn2＋ ions.Yihnaz et al. found that bound magnetic polarons are responsible to the RT-FM. Gao et al. reported that the exchange interaction between the donor electron trapped by the singly ionized oxygen vacancy and sur- rounding Mn ions is responsible for the RT-FM. It was also reported that the ferromagnetism of the Mn-doped ZnO nanowires could be controlled by the electric-field or Mn doping levels. This work will investigate the magnetic property of the Mn-doped ZnO nanowires grown by the chemical vapor deposi- tion （CVD） method under the air condition and under the vacuum condition, respectively, and it is found that crystalline quality plays an important role to-wards the room-temperature ferromagnetic behavior of the doped nanowires.     

Iron Halide Species Produced by Laser-Evaporation

Iron halide species were produced by the reaction of laser-evaporated iron atoms with halogen-containing reactant gas, and isolated in low-temperature matrices to obtain their Mössbauer spectra. Iron fluoride (Fe₂F₆, FeF₃ and Fe₂F₄) and iron iodide (FeI₂ and Fe₂I₄) were produced by the reaction of laser-evaporated iron atoms with sulfur hexafluoride SF₆ and methyl iodide CH₃I, respectively. The yields of the products varied depending on the concentration of reactant gas in the Ar matrix. Molecular orbital calculations were performed in order to confirm their assignments.     

Magnetic and Structural Properties of Fe–Mn–Al Alloys Produced by Mechanical Alloying

Hyperfine Interactions - The effects of concentration and preparation conditions on the magnetic and structural properties of samples of the Fe-Mn-Al system prepared by mechanical alloying were...