Ultrathin FePd (5 nm) films of equiatomic composition were prepared by magnetron sputtering on the SiO2 (100 nm)/Si (001) substrates at room temperature. Effect of environment (vacuum or hydrogen), temperature and annealing duration on the phase transformation from disordered A1 FePd phase into the ordered L10 FePd phase, structure, surface morphology and magnetic properties of the films were studied. In comparison with annealing in vacuum the hydrogen treatment accelerates the ordering process. Wherein, introduction of hydrogen atoms into the FePd film lead to change in electronic structure and causes a reversible effect on magnetic states: ferromagnetic ↔ paramagnetic. With an increase in the duration and temperature of annealing in hydrogen due to its reversible effect on magnetism, the magnetic properties and states change: soft magnetic → paramagnetic → hard magnetic → paramagnetic.

In this study, bilayer thin films with different layers' order, Ni/Ti/Si (100) and Ti/Ni/Si (100), are prepared by magnetron sputtering at room temperature followed by the thermal annealing in a vacuum in the temperature range from 400 degrees C to 600 degrees C for 1 h. The combination of XRD and SIMS techniques is used to investigate the effect of the layers' inverse arrangement on the crystalline structure, phase formation and elemental composition upon thermal treatment. As revealed, the annealing of the Ni/Ti bilayer leads to the diffusion of Ti atoms through the Ni grain boundaries towards the outer surface. For the case of Ti/Ni bilayer, interdiffusion between Ni and Ti is not detected upon heat treatment, whereas the thermally induced diffusion between Ni and substrate resulted in the formation of NiSi silicides is revealed. The likely structural and thermodynamic reasons for such behaviour are discussed.

The effect of the location of an additional Au layer (top, intermediate, and bottom) on the residual stresses, structure, the transformation of the disordered A1 phase into the ordered L10 FePt phase, and magnetic properties of layered FePt(15 nm)-Au films on SiO2(100 nm)/Si(001) substrate is investigated. The ordering processes in the films separated from the substrates during in situ annealing are studied as well. It is shown that the level of mechanical stresses depends on the Au layer location and the number of interfaces in FePt–Au films. Both films (on the substrate and separated from it) with an intermediate Au layer had the lowest temperature of the beginning of L10 phase formation. During annealing, diffusion of Au and its redistribution along the grain boundaries of the L10 FePt phase occur. An increase in the Au concentration along the grain boundaries reduces the exchange interaction between them and increases the coercivity of the FePt/Au and Au/FePt films.

A set of 20 composites was prepared by pyrolysis of Co2+ complexes with 1,10-phenanthroline, melamine and 1,2-diaminobenzene. These composites were tested as the catalysts for the hydrogenation of quinolines. As shown by powder X-ray diffraction and TEM, the composited contained Co particles of several dozen nm sizes. The composition (elements content), Raman spectra X-ray photoelectron spectra parameters of the composites were analyzed. It was found that there was no distinct factor that controlled the yield of 1,2,3,4-tetrahydroquinolines in the investigated process. The yields of the respective products were in the range 90-100 %. The three most active composites were selected for scale-up and hydrogenation of a series of substituted quinolines. Up to 97 % yield of 1,2,3,4-tetrahydroquinoline was obtained on a 50 g scale. Five representative substituted quinolines were synthesized on a 10-20 grams scale using the Co-containing composites as the catalysts.

In this work, the influence of an Ag layer, which is located at different positions of the layer stack (top, intermediate, bottom), on the structural and magnetic properties of ordered L10 phase in Fe50Pt50 films was investigated. It was found that the position of an additional Ag layer affects the stress state of the as-deposited FePt films. Mechanical stress is induced during deposition and post-annealing process due to the difference in thermal expansion coefficients and lattice mismatch of FePt, Ag, and substrate. The initial stress state affects the ordering process during subsequent heat treatment. The higher level of initial compressive stress (− 7.8 GPa) in FePt/Ag/FePt films results in L10 phase formation at a temperature of 700 °C which is about 100 °C lower than in films with Ag bottom (− 3.6 GPa) and top (+ 0.86 GPa) layers. A more pronounced (001) oriented growth of the L10 phase was observed in stacks with Ag top layer as compared to Ag bottom and intermediate layers. The highest values of coercivity were obtained for films with Ag intermediate and bottom layers, which is due to the distribution of Ag along FePt grain boundaries that result in strong exchange decoupling of FePt grains. Furthermore, the formation of the ordered L10 phase at comparatively low temperatures of about 370 °C was observed in a free-standing FePt/Ag (30 nm)/FePt film.

Исследованы особенности формирования структуры и фазового состава системы Cu(25 нм)/Cr(25 нм) при отжиге в вакууме в широком температурном интервале.Зафиксировано развитие окислительно-восстановительных процессов, которые можно эффективно контролировать путём использования дополнительной ионно-плазменной обработки.Низкоэнергетическое ионное воздействие позволяет также стабилизировать нанокристаллическую структуру путём торможения процессов рекристаллизации и таким образом повысить термическую стабильность рабочих плёночных элементов микро-и наноэлектронных устройств.

Crystal structure transformations in V(25 nm)/SiO2(001) and V(25 nm)/Ag(25 nm)/SiO2(001) thin films during annealing in vacuum of 10(-3) Pa in the temperature range from 400 degrees C to 600 degrees C have been investigated by synchrotron X-ray powder diffraction. Crystal lattice parameters of VOx phase were evaluated for all transformations stages as well as its tetragonality degree. Additional techniques such as in-situ electron diffraction, secondary ion mass-spectrometry and transmission electron microscopy have been applied as well. introduction of the Ag layer affects the V film structure and its oxidation property during annealing. The body-centered monoclinic (bcm) lattice forms in V films after annealing. On the other hand, presence of the Ag layer leads to formation of the body-centered tetragonal (bct) structure during annealing at the same temperature. Ag suppresses oxygen incorporation into the film during annealing due to its diffusion into V grain boundaries and following diffusion induced grain boundary migration, leading to decrease of vanadium grains size. Mentioned above structural changes have not been detected for samples annealed in a vacuum of 10(-7) Pa in the same temperature range. (C) 2018 Elsevier Ltd. All rights reserved.

Досліджено структуру тонких плівок ванадію на різних монокристалічних підкладинках V(25 нм)/SiO 2 (001), V(25 нм)/MgO(100), V(25 нм)/Al 2 O 3 (0001), V(25 нм)/SrTiO 3 (100) у вихідному стані та при відпалі до температури у 600 C у вакуумі 10 3 Па.Із використанням синхротронного випромінення (RIKEN SPring-8 Center) виявлено переважну орієнтацію зерен у напрямку [110] для плівки на підкладинці SrTiO 3 (100) із періодом кристалічної ґратниці у 3,024 Å, який відповідає масивному стану, і розміром областей когерентного розсіяння порядку 11 нм.У вихідному стані ступінь окиснення приповерхневих шарів визначається далекосяжним

Hybrid nanocomposites with different composition prepared from polyaniline (PAni) and exfoliated MoS2 and WS2 were prepared by a mechanochemical method and studied as electrodes of symmetrical supercapacitors (SSC). Nanoparticles of MoS2 and WS2 have been found to promote electrochemical reversibility of redox conversion in PAni at high potentials and contribute to the stability of these nanocomposites during prolonged charge-discharge cycling. The specific capacity of such materials can reach 600 F/g and the specific power of SSC can reach ~4.1 kW/kg for specific energy ~23.5 W·h/kg.

Оттиски доступнû непосредственно от издателя Ôотокопирование разрешено только в соответствии с лицензией  2017 ÈМÔ (Èнститут металлофизики им.Ã. В. Курдюмова ÍАÍ Óкраинû) Íапечатано в Óкраине.349 350 А. К. ОРЛОВ, І. О. КРÓÃЛОВ, І. Є. КОТЕÍКО та ін.transition metals used to form the topology of micro-and nanoelectronic devices and protect them from corrosion are discussed.

Stable colloidal solutions of gold in water and ethanol were produced in the presence of small amounts of linear polyethyleneimine (PEI). In aqueous solutions a lowering of PEI concentration from 0.05wt% to 0.0063wt% results in an increase of the average size of Au particles from 3–7nm to 30−40nm. In ethanol 5–10nm Au particles were produced in the presence of 0.0063–0.05wt% PEI. At 0.05wt% PEI the Au particles retain individual character but a lowering of PEI content to 0.0063wt% causes particle aggregation into 80–140nm globules. The Au–PEI nanoparticles exhibit catalytic activity in reduction of methylviologen bication to cation-radical by sulfide-ions as well as a co-catalyst of photocatalytic water reduction by ethanol with the participation of mesoporous TiO2. In both cases individual 4−8-nm Au–PEI particles show a much higher catalytic activity than 80−140-nm globules of aggregated Au–PEI NPs synthesized at a lower PEI content.

The nature of the solvent and the concentration significantly affect both the efficiency of the ultrasonic liquid-phase exfoliation of molybdenum disulfide and the structure of the resultant semiconductor particles. The reaction of MoS2 and H[AuCl4] in aqueous ethanol solution leads to the formation of MoS2/Au composite materials, whose morphology is a function of the preparative conditions of the oxidation-reduction reaction.

Monodisperse spherical nanoparticles of M II Fe 2 III O 4 (M = Mn, Co, Ni) with controlled diameter (5-20 nm) were synthesized by solvothermal decomposition of [M II Fe 2 III O(CH 3 CO 2 ) 6 (H 2 O) 3 ] complexes in poly- and tetraethylene glycol. The samples were studied by XRD, TEM, and SQUID magnetometry. The nanoparticles have superparamagnetic behavior. The blocking temperature, magnetization, and magnetic anisotropy barrier decrease, while the magnetic anisotropy constant increases with decreasing particle size.

It was shown that the conductivity of polyaniline can be increased significantly as a result of mechanochemical doping with camphorsulfonic acid and secondary doping with m-cresol in comparison with the conductivity of the polymer synthesized by the traditional method. The obtained polymer has a nanofibrillar structure and is characterized by a metallic type of temperature dependence of the conductivity over a wide range of temperatures.

By the methods of Auger-spectroscopy and mass-spectrometry of secondary ions, small-angle electron diffraction, X-ray and resistometry analyses the solid-state reactions in the Ti(5 nm)/ Ni(24 nm)/Si(001) thin film system at annealing in running nitrogen in the temperature interval of 723 – 1273 К are investigated. Regularities of phase transformations, consistency of solid-state reactions, layer-by-layer redistribution of components during annealing, features of surface morphology during formation of inclusions of silicide phases are established.

Influence-of the ultrasonic impact treatment (UIT) in-an-inert environment on the structure, phase composition and micromechanical properties of composite coatings fabricated by implantation of dispersed nickel and titan particles to the surface layers of the aluminium alloy D16 is studied. Both the mechanochemical reaction of intermetallic-compounds' formation and the process of the nanostructurizing of deformation composite runoff directly under the UIT action. The maximum effect of surface strengthening is of congruent to 250%.

Thermal decomposition of the trinuclear complex [Fe2CrO(CH3COO)6(H2O)3]NO3 at 300, 400 and 500°C gave γ-Fe2O3 nanoparticles along with amorphous chromium oxide, while decomposition of the same starting compound at 600 and 700°C led to the formation of α-(Fe2/3Cr1/3)2O3 nanoparticles. Size of γ-Fe2O3 nanoparticles, determined by X-ray diffraction, was in the range from 9 to 11nm and increased with formation temperature growth. Average size of α-(Fe2/3Cr1/3)2O3 nanoparticles was about 40nm and almost did not depend on the temperature of its formation. γ-Fe2O3 nanoparticles possessed superparamagnetic behavior with blocking temperature 180–250K, saturation magnetization 29–35emu/g at 5K, 44–49emu/g at 300K and coercivity 400–600Oe at 5K. α-(Fe2/3Cr1/3)2O3 nanoparticles were characterized by low magnetization values (2.7emu/g at 70kOe). Such magnetic properties can be caused by non-compensated spins and defects present on the surface of these nanoparticles. The increase of α-(Fe2/3Cr1/3)2O3 formation temperature led to decrease of magnetization (being compared for the same fields), which may be caused by decrease of the quantity of defects or non-compensated spins (due to decrease of particles' surface).