Спектроскопическое исследование кристаллов KY-=SUB=-3-=/SUB=-F-=SUB=-10-=/SUB=-, активированных празеодимом

We report on the high-resolution Fourier spectroscopy study of KY3F10:Pr3+ crystals. The analysis of the transmission and luminescence spectra allowed us to refine and supplement the information on the crystal-field levels of the Pr3+ ion. The value of the hyperfine splitting of the ground state of Pr3+ in the KY3F10 cubic matrix is estimated. The observed shape of the spectral lines indicates the presence of defects in the sample under study.

Preparation of quaternary compounds Cu2ZnSnS4 by using the self-propagating high-temperature synthesis

Possibility to prepare finely dispersed Cu2ZnSnS4 by using the method of self-propagating high-temperature synthesis has been studied in this work. Investigations of Raman scattering and IR-Fourier spectroscopy of the synthesized finely dispersed material have been carried out. The analysis of the Raman and IR-Fourier spectra showed that the synthesized material in the process of preparing is formed with a kesterite structure with the inclusion of a certain amount of secondary phases in the form of sulfides and stannites.

The IR Fourier spectroscopy of pine wood, struck with red belt fungus (Fomitopsis pinicola)

Методом ИК Фурье спектроскопии в пределах одного ствола были изучены изменения древесины cосны обыкновенной (Pínus sylvéstris) в результате ее биологического поражения и деструкции окаймленным трутовиком – грибом Fomitopsis pinicola (Schw. ex Fr.) Karst. Исследование проводили на спектрометре Prestige-21 фирмы Shimadzu в области волновых чисел 4000– 400 см–1 с разрешением 4 см–1 (20 сканов). Спектры поглощения снимали с использованием приставки диффузионного отражения (ДО). Показано, что биодеструкция древесной ткани сосны отражается на ИК Фурье спектрах. Изменения наблюдаются в областях спектра поглощения, характеризующих валентные колебания гидроксильных, метиленовых, карбонильных групп, скелетные колебания ароматического кольца. Глубокая деструкция древесины в центре ствола сопровождается батохромным сдвигом (1734 см–1 до 1719 см–1) и значительным увеличением интенсивности полосы поглощения валентных колебаний карбонильных групп (1719 см–1), а также изменением контура спектра поглощения в области от ~1719 до ~1100 см–1. В спектре деструктированной древесины интенсивности полос поглощения в этой области уменьшаются, в спектрах образцов с периферии и центра ствола, сохранивших морфологическую структуру древесины – увеличиваются. В деструктированной древесине отмечено существенное увеличение интенсивности полосы поглощения при 1601 см–1, которая становится несколько большей, чем интенсивность полосы с максимумом 1508 см–1, что не характерно для ИК спектра здоровой хвойной древесины, в которой отношение интенсивностей этих полос поглощения противоположное. Сhanges of the Scots pine wood (Pínus sylvéstris) within a single tree trunk caused by its biological destruction made by red belt fungus Fomitopsis pinicola (Schw. ex Fr.) Karst were studied by use of the IR Fourier spectroscopy method. The wood was cut in Syktyvdin region of the Komi Republic. From the trunk about 36 сm in diameter a sample was sawed about 15 cm thick. Three samples were selected for spectra: 1 – light brown non-destructed wood from the centre of the trunk, 2 – dark brown, adjacent to the completely destroyed wood; 3 – from the periphery of the trunk not clearly affected by rot. The research was made by use of spectrometer Prestige-21 produced by Shimadzu company in the field of the wave numbers 4000–400 сm–1 with a resolution of 4 cm–1 (20 scans). Absorption spectra were examined by using a diffusion reflector (DR). It is shown that bio destruction of the wood fiber of pine is reflected on the IR Fourier spectra. Changes are observed in the absorption spectrum that characterize the valence oscillations of hydroxyl, methylene, carbonyl groups, and skeletal oscillations of the aromatic ring. A deep destruction of wood in the centre of the trunk is accompanied by a bathwater drift (1734 сm–1 to 1719 сm–1) and a significant increase in the absorption band of the valence oscillations of carbonyl groups (1719 сm–1), as well as change of the spectra contour of the absorption from ~1719 to ~1100 cm–1. In the spectrum of the disrupted wood, the intensity of the absorption bands in this area decreases, and in the spectra of the samples from the periphery and the center of the trunk that have preserved the morphological structure of the wood increases. There is a significant increase in the absorption band in the disrupted wood 1601 сm–1, that becomes bigger than, band intensity maximum 1508 сm–1, that is not typical for the IR spectrum of healthy coniferous wood, in which the ratio of the intensity of these absorption bands is the opposite.

Identification of black microplastics using long-wavelength infrared hyperspectral imaging with imaging-type two-dimensional Fourier spectroscopy

We constructed a palm-sized LWIR hyperspectral camera with a microbolometer and successfully measured the absorbance of black microplastics.

The use of radiation-resistant materials in gas semiconductor Fourier spectroscopy for express analysis of rocket fuel in the production process on the Moon / Mars / asteroids

The paper considers the possibility of using thin films based on samarium sulfide, as well as composite systems of metal-oxide semiconductors doped with rare-earth elements, as radiation-resistant sensitive materials for monitoring leaks of rocket fuel components. The data of electrophysical studies of the obtained sensor layers were processed within the framework of the semiconductor Fourier spectroscopy constructed in relation to gas-analytical systems and the nonlinear regression algorithm of selective calibration. The latter solves really the problem of sensors’ selectivity including distinguishing the substances of the same homology such as methane, propane and n-hexane.