Structure and composition of arrays of vertically aligned multi-walled carbon nanotubes grown by continuous injection chemical vapor deposition method were studied using the high resolution transmission electron microscopy combined with energy dispersion spectrometry. A portion of injected Fe catalyst was found in the form of nanosized single crystalline particles with a variety of the structures of α-Fe(C), γ-Fe(C) and orthorhombic Fe 3 C phases encapsulated in the carbon nanotube channel or incorporated into the carbon nanotube wall. A thorough analysis revealed not only the lattice expansion of the γ-Fe(C) phase due to incorporation of carbon atoms but also a monoclinic distortion of the cubic lattice with orts c > a = b and square base transformed into a rhombic one. The monoclinic lattice distortion was referred to the uniaxial symmetry of the encapsulating tube. No evident coherency was observed in the atomic arrangement at the interface between Fe particle and inner shell of the carbon tube, as well as in the atomic arrangement of neighboring graphene shells of the carbon nanotube wall, meaning that the chirality of the shells is not coherent.

Two types of asymmetry in giant magnetoresistance (GMR) are observed which are not related to a training effect, but indicate different mechanisms of magnetization reversal of the pinned layer in spin-valve (SV) structures for ascending and descending field scans. GMR, exchange bias and coercivity in Si/Ta/NiFe/Cu/NiFe/IrMn/Ta SV-structures were investigated as functions of the thickness of the nonmagnetic spacer. The spacer thickness effects are discussed in correlation with layers microstructure and interfaces morphology variations.

A pulsed plasma plume obtained by pulsed laser irradiation of a Pt target was used to fabricate a hydrogen sensor on a 6H-SiC single crystal by means of ion implantation followed by thin film deposition. To realize the ion implantation, high voltage pulses with positive polarity were applied to the Pt target when the laser plasma expanded from the target to the SiC substrate. Experimental diagnostics of pulsed ion beams extracted from laser-produced plasma were performed and the structure of the SiC crystal after high-temperature (500 degrees C) ion implantation was studied by Rutherford backscattering spectroscopy of He-4(+) ions. At the same time, a one-dimensional model of the plasma movement in a pulsed electric field was developed and simulations were carried out using the particle-in-cell method. Modeling allowed determination of the ion energy distribution depending on the delay time of the high voltage pulse after the laser pulse. The calculated energy distribution of Pt ions was used to predict the depth profile of implanted Pt ions in the SiC substrate. The predicted profile agreed sufficiently well with the experimentally measured depth distribution of Pt in the SiC substrate. To characterize the fabricated SiC sensor, the current flow through a barrier structure was studied. The volt-ampere characteristics of the structure were measured in air and in a mixture of air and hydrogen (2%) at a temperature of 500 degrees C. The characteristic value of the change in voltage exceeded 2 V at the bias current of 1 mA when hydrogen was added to the air. The response of the sensor to the hydrogen was stable after long-term tests while the structure of the Pt film was disturbed. The ion-implanted layer operated as a series resistance, which had a significant effect on the current flow through the barrier structure. The resistance decreased under the influence of hydrogen and persisted during long-term tests. (C) 2013 Elsevier B.V. All rights reserved.

An experimental setup for medium energy ion scattering spectroscopy allowing materials elemental composition diagnostics has been developed. A target composed of single-crystalline Ge with a smooth surface and structural inhomogeneity several nanometers thick has been prepared for conducting the experiments. Experiments have shown that the depth resolution of the method was 6 Å.

In this work, we study the structure of submicron titanium-nitride films after surface treatment with a nitrogen-ion beam. It is ascertained that nitrogen-ion beams affect two-phase TiN-Ti films thus transforming them into single-phase TiN.

Введен в строй экспериментальный комплекс, на котором реализована методика диагностики элементного состава материалов – спектроскопия рассеяния ионов средних энергий. Для проведения экспериментов приготовлена мишень из монокристаллического Ge с гладкой поверхностью и структурной неоднородностью в слое толщиной в несколько нанометров. Эксперименты показали, что разрешение метода по глубине составляет 6 A.

The chemical homogeneity of TiN thin films produced by the sputtering of a titanium target in a nitrogen atmosphere are studied using atomic-force microscopy and the backscattering of helium ions. It is established that TiN films of submicron thickness contain titanium nanoparticles, the number of which increases with decreasing nitrogen pressure.

Исследована химическая однородность пленок TiN, полученных путем вакуумно-дугового распыления титановой мишени в атмосфере азота, с помощью атомно-силовой микроскопии и метода обратного рассеяния ионов гелия. Установлено, что в пленках TiN субмикронной толщины присутствуют наночастицы титана, количество которых возрастает с уменьшением давления азота.

An efficient method is described of growing of vertically aligned carbon nanotubes (VANTs) densely packed on a large area with uniform height up to 1mm. The method is based on injection of active solution of ferrocene in cyclohexane into reactor during the growth process. We also describe a method of ER/VANTs composite preparation based on infiltration of epoxy resin (ER) liquid monomer into arrays of the VANTs forest with polymerization followed. Further on we describe a press-and-draw method to reorient VANTs into horizontally aligned carbon nanotubes (HANTs) in the liquid composite precursor. The electrical conductivities up to 0.6S/cm in ER/VANTs and up to 0.85S/cm in ER/HANTs are obtained.

Исследовано влияние термообработки на свойства приповерхностного слоя Si, легированного ионами Zn. Радиационные дефекты и профили примеси цинка были исследованы методом резерфордовского обратного рассеяния с использованием техники каналирования. Морфология образцов была изучена с помощью атомно-силового микроскопа и растрового электронного микроскопа в режиме вторичных электронов. Фазовый состав образцов был определен методом рентгеновской дифракции в скользящей геометрии.

Results of temperature treatment effect on near surface layer properties of Zn ion implanted Si substrate are presented. Radiation induced point defects and Zn in depth profile was studied by Rutherford back scattering (RBS) method with use of channeling technique. Topology of substrate surface was studied by atomic force microscopy (AFM) and scaning electron microscope (SEM). Phase composition of samples was test by x-ray diffraction in grazing geometry.

With the help of the PIXE and RBS methods, the elemental composition of a ceramic coating on Zr alloy, surface layers of heat-treated TiNi alloy, and Ar + implanted pyrolytic graphite is investigated. It is shown that the PIXE and RBS methods are complementary and their combined use can provide additional information on the elemental composition of the surface layers. It was determined that the microarc oxidation of Zr alloy in an electrolyte with addition of ultrafine Y 2 O 3 powder leads to introduction of Y in the substrate material. An effect of the surface segregation of Ti was found in TiNi alloy after the heat treatment.

Formation of rodlike structures elongated in the 〈100〉 and 〈010〉 directions of silicon crystal was observed during magnetron codeposition of carbon and nickel on (100) silicon substrate with a natural oxide layer. Rodlike structures did not form during deposition in similar conditions on (111) silicon substrate. It has been revealed that the rodlike structures represent epitaxial nickel silicide precipitates. The results of experimental study of the composition, structure, and shape of forming silicide clusters as a function of the silicon substrate orientation and the codeposited layer thickness are presented.