Showing papers by "Sergey M. Zharkov published in 2014"
TL;DR: In this paper, a resistive switching effect was found in the tunneling spectra measured in air at the smaller uncapped Ag NPs deposited on HOPG and was interpreted in terms of Ag transfer between the particle and the probe.
59 citations
TL;DR: In this paper, the structural and magnetic properties of the epitaxial structure of a single-crystal Fe3Si silicide film with the orientation Si[111] was identified using X-ray structural analysis, transmission electron microscopy, and reflection high-energy electron diffraction.
Abstract: The results of the structural and magnetic studies of the epitaxial structure prepared during the simultaneous evaporation from two iron and silicon sources on an atomically pure Si(111)7 × 7 surface at a substrate temperature of 150°C have been presented. The epitaxial structure has been identified as a single-crystal Fe3Si silicide film with the orientation Si[111]‖Fe3Si[111] using methods of the X-ray structural analysis, transmission electron microscopy, and reflection high-energy electron diffraction. It has been established that the epitaxial Fe3Si film at room temperature has magnetic uniaxial anisotropy (Ha = 26 Oe) and a relatively narrow uniform ferromagnetic resonance line (ΔH = 11.57 Oe) measured at a pump frequency of 2.274 GHz.
27 citations
TL;DR: In this article, the formation of the hard-magnetic ordered L10-FePd phase in thin bilayer Pd/α-Fe(001) films has been experimentally studied.
Abstract: The formation of the hard-magnetic ordered L10-FePd phase in thin bilayer Pd/α-Fe(001) films has been experimentally studied. Solid-state reactions initiated by thermal heating in bilayer Pd/α-Fe(001) films with a thickness of 50–60 nm (the atomic ratio Pd: Fe ≈ 50: 50) separated from the substrate have been studied using the in situ electron diffraction methods. It has been shown that the solid-state reaction between the palladium and iron layers in Pd/α-Fe(001) starts at 400°C with the formation of the disordered Fe-Pd phase. At 480°C, the ordered L10-FePd phase is formed. The order-disorder phase transition has been studied. It has been established that the transition of the ordered L10-FePd phase to the disordered FePd phase starts at 725°C. At 740°C, only the disordered FePd phase is present over the whole volume of the film. The observed temperature of the order-disorder phase transition is shifted from the equilibrium value by 35°C to higher temperatures. This effect is assumingly associated with the higher concentration of palladium atoms at the boundaries of the Fe-Pd crystal grains owing to the grain-boundary adsorption.
18 citations
TL;DR: In this article, the solid-state reaction between the nanolayers of iron and silicon has been established to begin at 350-450oС increasing with the thickness of the iron layer.
Abstract: Solid-state reaction processes in Fe/Si multilayer nanofilms have been studied in situ by the methods of transmission electron microscopy and electron diffraction in the process of heating from room temperature up to 900oС at a heating rate of 8-10oС/min. The solid-state reaction between the nanolayers of iron and silicon has been established to begin at 350-450oС increasing with the thickness of the iron layer.
12 citations
TL;DR: In this paper, the effect of the freezing of magnetic moments of nanocubes and nanocrystalline particles constituting nanoclusters was examined by transmission electron microscopy, magnetic measurements, and magnetic resonance over a wide frequency range 9.6-80 GHz and at temperatures down to 4.2
Abstract: Nanoclusters and nanocrystals of the room temperature magnetic spinel CuCr2S4 synthesized using a facile solution-based method have been examined by transmission electron microscopy, magnetic measurements, and magnetic resonance over 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 below 50 K for both samples are due to the freezing of magnetic moments of nanocubes and nanocrystalline particles constituting nanoclusters. The effective fields of averaged magnetic anisotropy ⟨HA⟩≅ 2.4 kOe are similar for both nanopowder samples as estimated from resonance measurements at T = 4.2 K. An additional blocking temperature Tb ≅ 300 K appears in nanoclusters due to freezing of the magnetic moment of the entire cluster as a whole. Below this blocking temperature, the magnetic dipolar field acting in boundary areas of interacting constituent nanocrystals is responsible for the additional low-field resonance line observed in th...
8 citations
TL;DR: In this article, the magnetic properties of three-layer Co-Ge magnetic films have been studied experimentally as a function of technological conditions of their deposition, and it has been found that the films deposited at a high deposition rate have a granular structure, and the films obtained at a low deposition rate had an X-ray amorphous structure.
Abstract: The magnetic properties of three-layer Co-Ge magnetic films have been studied experimentally as a function of technological conditions of their deposition. It has been found that the films deposited at a high deposition rate have a granular structure, and the films obtained at a low deposition rate have an X-ray amorphous structure. Electron microscopy and nuclear magnetic resonance studies have demonstrated that, at the same cobalt layer thickness, the semiconductor granule sizes depend on the average semiconductor layer thickness and correlate with the formation of different cobalt phases (amorphous, cubic, and hexagonal). The thermomagnetic properties of the films have been investigated.
7 citations
TL;DR: In this article, it was found that metastable equilibrium in the heterogeneous reaction PdCl4-hydrochloric acid solutions at 60°C depended on the dispersity of metallic palladium.
Abstract: It was found that metastable equilibrium in the heterogeneous reaction PdCl
4
2−
+ 2e = Pd0 + 4Cl− in H2PdCl4-hydrochloric acid solutions at 60°C depended on the dispersity of metallic palladium. It was shown experimentally that the dependence of the shift of the PdCl
4
2−
/Pd0 redox potential on the dispersity of palladium(0) was described by the Thomson equation.
3 citations
TL;DR: In this article, the morphology and structure of the interface in Ni/Ge thin films being due to the mutual diffusion of these elements are investigated with the help of atomic force microscope, high resolution electron microscope and microdiffraction.
Abstract: Morphology and structure of the interface in Ni/Ge thin films being due to the mutual diffusion of these elements are investigated with the help of atomic force microscope, high resolution electron microscope and micro-diffraction. Strong effect of interface in magnetic behavior of Ni layers is demonstrated and explained by formation of magnetic order in the interface and rough boundaries between layers.
2 citations
TL;DR: In this paper, the structural and magnetic properties of (Fe/Si) nano-structures obtained by successive deposition on the SiO2/Si(100) surface at a temperature of the substrate of 300 K have been studied.
Abstract: The structural and magnetic properties of (Fe/Si)
N
nanostructures obtained by successive deposition on the SiO2/Si(100) surface at a temperature of the substrate of 300 K have been studied. The thicknesses of all Fe and Si layers have been determined by transmission electron microscopy measurements. The magnetic properties have been studied by the X-ray magnetic circular dichroism (XMCD) method near the Fe L
3, 2 absorption edges. The orbital (m
l
) and spin (m
S
) contributions to the total magnetic moment of iron have been separated. The thicknesses of magnetic and nonmagnetic iron silicide on the Si/Fe and Fe/Si interfaces have been determined with the surface sensitivity of the XMCD method and the model of the interface between the nonmagnetic and weakened magnetic phases.
2 citations
TL;DR: In this article, magnetic circular dichroism (MCD) was investigated in the spectral range 1.2 - 4.2 eV in a field of about 3 kOe.
Abstract: Co and Ni nanoparticles were fabricated in fused silica plates by ion implantation technique. Electron microscopy showed the nanoparticles to be of spherical shape. Magnetic circular dichroism (MCD) was investigated in the spectral range 1.2 - 4.2 eV in a field of about 3 kOe. MCD spectra are considerably different from the spectra of thin nickel and cobalt films. MCD spectra for Ni nanoparticles are associated with surface plasmon resonance.
1 citations
TL;DR: In this paper, it was shown that 6H-SiC nanowires grow from the arc plasma, as well as from the vapor, according to the known mechanism of vapor-solid condensation on a cold surface covered with single-crystal silicon carbide nuclei.
Abstract: Silicon carbide 6H-SiC nanoparticles and nanowires were obtained in carbon-silicon high-frequency arc plasma plasma in a helium atmosphere at a pressure of 0.1–0.6 MPa. It was shown that 6H-SiC nanowires grow from the arc plasma, as well as from the vapor, according to the known mechanism of vapor-solid condensation on a cold surface covered with single-crystal silicon carbide nuclei. The content of silicon carbide nanowires in the condensate reached 60 wt %. The obtained single-crystal silicon 6H-SiC nanowires had the diameter of 15–18 nm and length of 200–600 nm.