A graphical interface program has been developed to determine the linear-polarization factor of a monochromatic X-ray beam when analyzing scattering from an amorphous object. An area coordinate ...detector is used in measurements. The change in intensity over the azimuthal angle at a constant diffraction angle is interpolated by a theoretical cosine dependence, which contains the polarization factor.
Full text
Available for:
DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, SIK, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Photosemiconductor thin films based on two organic porphine derivatives have been investigated. These compounds have different pendent groups; the film morphology, along with the specific fabrication ...technique, is determined to a great extent by these groups. The films have been fabricated by vacuum sputtering and using the Langmuir−Schaefer method. According to the atomic force microscopy (AFM) data, the Langmuir−Schaefer films are more homogeneous than the sputtered ones. It is shown that the sputtered films based on substituted porphine have a looser stacking than the initial analog. A spectroscopy study revealed a bathochromic shift of the Soret band in the Langmuir−Schaefer films–sputtered films series. This shift is explained by the increase in the concentration and size of molecular aggregates in sputtered films. It is shown that a polycrystalline C
60
fullerene film deposited onto an amorphous substituted porphine layer improves the photoelectric characteristics of the latter. Both the time stability of the photodiode structure and its ampere‒watt sensitivity increase (by a factor of 10 in the transition regime). The steady-state current does not change. The effect of polarity reversal of the photovoltaic signal is observed in a planar С
60
‒substituted metalloporphine heterostructure, which is similar to the pyroelectric effect. The polarity reversal can be explained by the contribution of the trap charge and discharge current at the interface between the amorphous photosemiconductor and crystalline photosemiconductor to the resulting photoelectric current.
Full text
Available for:
DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, SIK, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Synchrotron X-ray diffraction studies of the structural characteristics of Ba
3
TaFe
3
Si
2
O
14
langasite are performed at high hydrostatic pressures (up to 60 GPa) created in a diamond anvil cell. ...At pressures up to 20 GPa, the Mössbauer absorption spectra for
57
Fe nuclei and the Raman spectra are recorded. Two structural phase transitions at
P
≈ 5.5 and 20 GPa are observed. The first transition corresponds to the displacements of light oxygen atoms and to an increase in the local symmetry of 3
f
oxygen tetrahedra surrounding iron ions. The second one is accompanied by a pronounced change in the lattice parameter
c
, and the unit cell volume undergoes a stepwise drop as large as 8.6%. An appreciable decrease in the parameter
c
at the structural transition should result in a significant increase in the exchange coupling constants between iron ions in neighboring
ab
planes underlying the giant increase in the Néel temperature in this crystal at pressures exceeding 20 GPa.
Full text
Available for:
DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, SIK, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
It is shown for the first time that the addition of ultrasmall amounts of single-wall carbon nanotubes leads to a significant increase in the main mechanical characteristics of the crosslinked ...poly(urethane urea) elastomer. The elastic modulus and the tensile strength pass through maxima as the nanotube concentration is increased from 0 to 0.018 wt %; at a nanotube concentration of 0.002 wt %, the maximum values of the modulus and strength are higher by factors of 2.5 and 1.5, respectively, than the corresponding values for the unfilled polymer. The thermomechanical, spectral, and structural characteristics of nanomodified elastomers are investigated, and possible causes of change in their mechanical parameters are discussed.
Full text
Available for:
EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Arrays of aligned carbon nanotubes (CNTs) and nitrogen-doped carbon (CNx) nanotubes have been grown on silicon substrates as the result of thermolysis of ferrocene/toluene and ferrocene/acetonitrile ...mixture. The microstructure of materials was studied by transmission and scanning electron microscopy, and X-ray diffraction was used to control the carbon and iron forms. The composition and properties of iron nanoparticles developed in the CNT and CNx nanotube samples were determined from Mössbauer spectroscopy data. The total iron content in CNx nanotubes was found to be considerably higher than that in CNTs. Three forms of iron nanoparticles α-Fe, γ-Fe, and Fe3C were detected in CNTs and only two last of them in CNx nanotubes. In the interior of CNT channels the α-Fe and Fe3C nanoparticles were observed to be coupled by a strong exchange interaction and to exhibit magnetic behavior at room temperature.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Standard specimens based on Au and ZnO nanoparticles are developed for calibration of low-angle x-ray diffractometers. Structural parameters of the standard specimens obtained are measured by means ...of transmission electron microscopy. Average values of nanoparticle dimensional parameters are confirmed, and additional characterization of standard specimens is achieved using a set of research methods, including optical spectroscopy, x-ray analysis, and synchrotron radiation.
Full text
Available for:
CEKLJ, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Using the previously described experimental setup for investigation of thermophysical properties of refractory materials under high pressures and temperatures a few experiments with samples of cast ...eutectic Re-C were carried out. The experimental technique was extended for millisecond electrical heating of the samples under the high static pressure of inert gas. First experimental data on the specific enthalpy, specific heat capacity and linear thermal expansion of ReC0.3 were obtained.
Nanostructured spherical calcium carbonate particles with average sizes of 3.8 µm and 550 nm have been fabricated. Optimal conditions for adsorption of central anesthetic loperamide on these ...particles are found. The influence of particle size on the adsorption efficiency is studied. The efficiency of micron and submicron vaterite particles as carriers for intranasal loperamide delivery is compared using in vivo tests on laboratory animals.
Full text
Available for:
DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, SIK, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
An oxygen-containing CeF
3
-based solid electrolyte with the composition Ce
0.95
Gd
0.05
O
0.075
F
2.85
has been prepared by Bridgman growth from a melt using a Gd
2
O
3
-containing starting mixture, ...and its ionic conductivity σ has been measured. The σ of the oxyfluoride at 400°C is 5 × 10
−3
S/cm, which is }~ 200 times the σ of single crystals of the well-known superionic oxide conductor Zr
0.88
Y
0.12
O
1.94
. The present results demonstrate the feasibility of obtaining a large number of oxyfluoride solid electrolytes based on rare-earth trifluorides with the tysonite (LaF
3
) structure via reactions between fluorides and oxides (of the same rare-earth element or different rare earths) in a melt, followed by melt solidification. They can be proposed as gasimpermeable conducting membranes of low-temperature potentiometric oxygen sensors.
Full text
Available for:
DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
PDF
