The article analyzes the infrared spectra (IR spectra) of detonation nanodiamonds (DND) obtained from various explosives: from an alloy of TNT and RDX; tetryl; tetryl with RDX and a ternary mixture: a mixture of TNT, RDX and tetryl. The resulting DNDs were treated: with aqueous ammonia at 220 °C at 40 atm, in a gaseous medium (air and argon) at 430 °C. It was shown that high-temperature treatment of various DNDs leads to an identical result: all nanodiamond samples, regardless of the initial explosive and the nature of the modification, have strong absorption bands of nitrogen impurity centers (826, ~1100, 1255, 1328, 1558 cm –1). In addition, all samples have pronounced absorption bands of adsorbed water (1625–1637 cm–1), carbonyl group (1742–1790 cm–1), stretching vibrations of the Csp3–H group (2853–2958 cm–1), and stretching vibrations of the OH group (3330 – 3397 cm–1).

Dependence of the g-Factor of Mineral Coals on a Metamorphism Level

The natural process of any metamorphism of carbonaceous matter is a complex chain of physical-chemical transformations where the most important are the physical and chemical transformation (CH) - (C) phases and the final structuring of the system carbon that is called metamorphism [1]. As a result of metamorphism, the oil shale is converted to a brown coal and the brown coal is converted to a coal and finally become anthracite.

Монгол орны нүүрсний ордууд болох Алагтогоо, Алагтолгой, Багануур, Нарийнсухайт, Нүүрсхотгор, Налайх, Шарын гол, Тавантолгой, Хартарвагатай, Хөшөөтийн нүүрсний электроны парамагнитын резонансын (ЭПР) туршлагын үр дүнг дэлгэв. ЭПР спектрийн гол параметрүүд болох ЭПР шугамын өргөн, g-фактор болон ЭПР шугамын өргөн ба эрчим микродолгионы хэмжээнээс хэрхэн хамаарахыг үзүүлэв.

Особенности радиоспектроскопии каменных углей низкойстепени метаморфизма

FP-9120 positive photoresist films 1.8 μm thick implanted with boron and phosphorus ions deposited onto the surface of KDB-10 single-crystal (111) silicon wafers by centrifugation are investigated by their conductivity and electron spin resonance measurements. It is shown that the Р+ ion implantation leads to the formation of a layer with an electronic conductivity of about 10−9 Ω−1 cm−1. At a phosphorous implantation dose of 6 × 1015 cm−2, the electron spin resonance spectrum contains a narrow isotropic line with a g factor of 2.00654 and a width of 3.83 G, which is most likely related to the formation of phenoxy radicals. As the implantation dose increases to 1.2 × 1016 cm−2, a line with a g factor of 2.00264 and a width of 3.96 G is detected in the electron spin resonance spectrum, which is caused by unpaired electrons delocalized according to the π-polyconjugated system.

TiO2:MoO3 nanocomposites with MoO3 content in the range of 0.1-10 mol.% were synthesized using sol-gel technology. The role of the structural peculiarities of TiO2:MoO3 composite in hydrogen adsorption and catalytic oxidation was discussed. Possibility of the selective oxidation of hydrogen in the presence of methane in the atmosphere was demonstrated.

Pure semiconductor tungsten oxide (WO3), indium oxide (In2O3) and mixed nanocomposites with different WO3 to In2O3 ratios were successfully synthesized by simple sol-gel method following calcination at 600 degrees C. The morphology, phase composition and features of crustal structure of the materials were studied by X-ray diffraction, Fourier-transform infrared spectroscopy, scanning electron microscopy, transition electron microscopy and electron paramagnetic resonance spectroscopy. It was found that the nanocomposite materials are characterized by fine crystallinity of 8-38 nm, highly defective crystal cells and presence of delocalized electrons in their structures, which can significantly affect gas sensitivity. The gas sensors based on WO3-In2O3 composite structures exhibited excellent CO and NO2 detecting performance at optimal operating temperature of similar to 240 degrees C and similar to 140 degrees C, respectively.

Electron paramagnetic resonance (EPR) and scanning electron microscopy (SEM) methods were used to study polyethylene terephthalate (PET) films implanted with 60 keV phosphorus ions in the dose range of 100–2000 μC/cm^2. The effect of irradiation on paramagnetism and on the change in the conductive properties of PET films was detected by a change in the frequency of the resonator and the amplitude of the EPR signal of a reference ruby sample controlling the quality factor of the resonator. It was found that the EPR signal in the spectra of irradiated films has a maximum intensity when implantation of phosphorus ions with a dose of 1000 μC/cm^2. The maximum losses in the resonator, indicating the presence of a conducting phase in the sample, are observed when measuring a PET film implanted with phosphorus ions with a dose of 200 μC/cm^2. Using SEM, it was found that when the samples are irradiated with phosphorus ions, carbon clusters are formed already at a dose of 200 μC/cm^2. The formation of a conductive layer in PET is indicated by a decrease in the frequency of the resonator and the amplitude of the EPR signal of the ruby standard. The dependence of the amplitude of the EPR signal of the standard, both on the dose of implanted ions and on the position of the implanted film relative to the direction of the external polarizing magnetic field, was found. The anisotropy of the paramagnetic properties of PET films implanted with phosphorus ions may indirectly indicate a magnetoresistive effect in them.

We have used electron paramagnetic resonance (EPR) to study high-purity detonation nanodiamond (DND) powders at room temperature. In recording the EPR signal with g factor 2.00247 and line width 0.890 mT, with automatic frequency control locking the frequency of the microwave generator (klystron) to the frequency of the experimental cavity, we observed a change in the shape of the EPR signal from the DND powder due to formation of an anisotropic electrically conducting structure in the powder. The electrical conductivity of the DND sample is apparent in the Dysonian EPR lineshape (strongly asymmetric signal with g factor 2.00146 and line width 0.281 mT) together with an abrupt shift of the baseline at the time of resonant absorption, and in the decrease in the cavity Q due to nonresonant microwave absorption. The observed effect can be explained by transition of the DND powder from a dielectric state to a state with metallic conductivity, due to spin ordering in a preferred direction.

Powders of boron-doped and phosphorous-doped detonation nanodiamond and sintered pellets made of non-doped nanodiamond powders were studied by the electron magnetic resonance and X-ray diffraction methods. The possibility of doping of the detonation nanodiamond crystal by boron and phosphorous was demonstrated. The possibility to use these methods for diagnostics of the doped diamond nanocrystals during shock-wave synthesis has been established.

Powders of boron- and phosphorus-doped detonation nanodiamonds and sintered pellets of non-doped nanodiamond powders were studied using electron paramagnetic resonance and x-ray diffraction. Doping of detonation nanodiamond crystals with boron and phosphorus was demonstrated to be possible. These methods could be used to diagnose diamond nanocrystals doped during shock-wave synthesis.

Photoinduced processes in thin films of MoO3 and mixed V2O5: MoO3 oxides prepared by polycondensation of the respective oxoacids under solvothermal conditions are studied using Raman spectroscopy, ESR, and AFM. It is shown that, under UV irradiation, the photoinduced polycondensation occurs in the oxide films, leading to the formation of the oxygen bridges, an effect that opens up the possibility of developing a new photolithographic process.

Samples of detonation nanodiamonds modified during the synthesis by adding doping elements in various ways have been studied by spectroscopic methods (electron paramagnetic resonance, Raman scattering, and X-ray diffraction). For the first time, the presence of P1 centers in detonation nanodiamond crystals has been indirectly demonstrated. The authors discuss the nature and distribution of spins as observed by the electron paramagnetic resonance, the composition of phases and size of the coherent scattering region, and crystal density (calculated by the X-ray method) of the detonation nanodiamond samples at hand.

The nature and character of changes during thermal annealing of paramagnetic centers in TiO 2 –MoO 3 gas-sensing materials with 1–10 mol% MoO 3 content were studied. The results suggested that certain processes occurred in the sensor during thermocatalytic detection of combustible gases. It was found that an increase of the sensor output signal in the temperature range 200–350°C was due to active participation of MoO 3 lattice oxygen in catalytic hydrogen oxidation processes.