— We report an experimental study concerned with the synthesis and luminescence properties of Al 5 O 6 N aluminum oxynitride doped with Tb 3+ in the concentration range 0.025–0.5 at %. All of the samples, prepared by firing appropriate mixtures in a nitrogen atmosphere at 1600°C, consisted predominantly of phase-pure γ-ALON (Al 5 O 6 N), with small amounts of impurity phases: Al 7 O 3 N 5 aluminum oxynitride and Tb 3 Al 5 O 12 terbium aluminate. Their pulsed cathodoluminescence and photoluminescence spectra contain emission bands typical of Tb 3+ ions. The concentration threshold for luminescence quenching corresponds to a Tb 3+ concentration at a level of 0.4 at %. A Tb 3+ cross relaxation effect found in Al 5 O 6 N:Tb 3+ is discussed and photoluminescence spectra are shown to be inhomogeneous at low Tb 3+ concentrations in Al 5 O 6 N.

Методами просвечивающей электронной микроскопии и микродифракции исследованы нанотонкие пространственные диссипативные структуры (ПДС), полученные термоградиентной обработкой аморфной плёнки селена путём одностороннего нагрева её нижней поверхности при Т = 413 К. Установлено, что полученные нанотонкие ПДС гексагонального селена обладают специфическим искривлённым габитусом и нелинейной веерообразной системой изгибных контуров на их электронно-микроскопическом изображении; решётка нанотонких ПДС испытывает упругопластическое ротационное искривление вокруг трёх взаимно перпендикулярных направлений; углы ротации решётки нанотонких ПДС гексагонального селена достигают: вокруг [001] 25o, вокруг направления, перпендикулярного [001] и лежащего в плоскости аморфной плёнки, 32o, вокруг направления, перпендикулярного первым двум и не лежащего в плоскости аморфной пленки, 35o.

Nanothin spatial dissipative structures (SDSs) produced by thermal gradient processing of an amorphous selenium film by means of one-sided heating of its lower surface at T = 413 K have been studied by transmission electron microscopy and microdiffraction. It has been established that the resulting nanothin SDSs of hexagonal selenium possess a specific curved habit and a nonlinear fan-shaped system of bending contours in their electron-microscopic image; the lattice of nanothin SDSs undergoes elastic-plastic rotational curvature around three mutually perpendicular directions; the lattice rotation angles of nanothin SDSs of hexagonal selenium reach 25° around [001], 32° around the direction perpendicular to [001] and lying in the plane of the amorphous film, and 35° around the direction perpendicular to the first two directions and not lying in the plane of the amorphous film.

Polycrystalline Al5O6N samples have been prepared by sol–gel synthesis followed by carbothermal reduction and nitridation. X-ray luminescence (XRL) spectra and thermoluminescence (TL) curves of Ce3+- and Eu2+-doped aluminum oxynitride have been measured in the temperature range 5–380 K and analyzed. Working TL peaks have been detected in the range 150–250 K for the Al5O6N:Ce3+ sample and in the range 140–200 K for the Al5O6N:Eu2+ samples. There are also lower temperature peaks: in the ranges 10–60 and 20–100 K. The XRL spectra of the samples have been measured at temperatures of 8 (for the first time) and 300 K.

Nanothin space-dissipative structures (SDSs) of hexagonal selenium formed in an amorphous film are investigated by transmission electron microscopy. It is established that the nanothin SDS of hexagonal selenium with a linear fan-shaped system of flexural contours in the electron-microscopy image is initial for the formation of the nanothin SDS of hexagonal selenium with a nonlinear fan-shaped system of flexural contours in the electron-microscopy image. It is shown that the formation of the nanothin SDS of hexagonal selenium with a nonlinear fan-shaped system of flexural contours in the electron-microscope image results in a change in the geometry of the nanothin-SDS lattice from Euclidean to Riemannian.

Herein we report the synthesis of aluminum oxynitride (Al5O6N) doped with Eu2+ and Ce3+ and examine the effects of the dopant concentration and the nature of the rare-earth-containing precursor (europium and cerium oxides, Eu(acac)3, and Ce(acac)3) on its properties. At dopant concentrations above the solubility limit of rare-earth aluminates (EuAl12O19 and CeAl11O18) in aluminum oxynitride, we observed the formation of aluminum nitride and aluminum oxide (α-Al2O3) as individual phases. The concentration of the latter phase was higher when the rare-earth oxides were used. The emission intensity in the cathodoluminescence spectra of the samples was shown to have a maximum at Eu2+ and Ce3+ concentrations from 0.1 to 0.5 at %. Concentration quenching of luminescence was observed.

Выполнен синтез и исследованы свойства оксинитрида алюминия (Al5O6N), легированного Eu2+ и Ce3+, в зависимости от концентрации и природы РЗЭ-содержащего компонента (оксидов европия и церия, Eu(acac)3, Ce(acac)3). Показано, что при концентрациях легирующего компонента, превышающих порог растворимости в оксинитриде алюминия алюминатов РЗЭ (EuAl12O19 и CeAl11O18), наблюдается образование индивидуальных фаз нитрида и оксида алюминия ( -Al2O3), содержание которого больше при использовании оксидов РЗЭ. Зависимости интенсивности испускания в спектрах катодной люминесценции от концентрации Eu2+ и Ce3+ демонстрируют наличие максимумов в области от 0.1 до 0.5 ат. %. Наблюдается эффект концентрационного тушения люминесценции.

Подготовлено кафедрой экспериментальной физики ФТИ при поддержке Центра интеллектуальной собственности и Института инноватики и маркетинга УрФУ.

Four rubidium and cesium vanadates, with the compositions Rb5V3O10, Rb3V5O14, Cs5V3O10, and Cs2V4O11, have been synthesized and identified, and their thermal stability ranges have been determined. Their spectroscopic properties and luminescence kinetics have been studied: we have measured their X-ray luminescence spectra at room temperature and liquid-nitrogen temperature, photoluminescence spectra, and photoluminescence excitation spectra. The spectra are compared to those of RbVO3 and CsVO3—phosphors that have optimal properties among the alkali metal vanadates.

Синтезированы, аттестованы и установлены термические интервалы стабильности четырех ванадатов рубидия и цезия состава Rb5V3O10, Rb3V5O14, Cs5V3O10, Cs2V4O11. Изучены их спектрально-кинетические свойства: измерены спектры рентгенолюминесценции (РЛ) при комнатной температуре и температуре жидкого азота, спектры фотолюминесценции (ФЛ) и возбуждения фотолюминесценции (ВФЛ). Проведено сравнение полученных данных со спектрами RbVO3 и CsVO3 – люминофоров, оптимальных среди метаванадатов щелочных металлов.

We have developed processes for the synthesis of the Rb 2 Zn(VO 3 ) 4 and Cs 2 Zn(VO 3 ) 4 tetrametavanadates. Rb 2 Zn(VO 3 ) 4 has been prepared by solid-state reaction (350°C) between presynthesized RbVO 3 and ZnV 2 O 6 powders, and Cs 2 Zn(VO 3 ) 4 has been prepared by the Pechini method (sol-gel process). Both metavanadates crystallize in monoclinic symmetry (sp. gr. P 2 1 / m ). Thermochemical characterization results demonstrate that the vanadates undergo complex transformations during heating to 450°C and subsequent cooling. As a result, the materials are in a nonequilibrium state at room temperature and consist of both the parent double metavanadates and their peritectic decomposition products. We believe that the formation of the structure of the M 2 Zn(VO 3 ) 4 compounds from their melts is a kinetically hindered process. These compounds are structurally stable only at temperatures below 369 (Rb 2 Zn(VO 3 ) 4 ) or 420°C (Cs 2 Zn(VO 3 ) 4 ). We have measured for the first time the diffuse reflectance and photoluminescence excitation spectra of the two tetrametavanadates in their emission range and their photoluminescence spectra at various excitation wavelengths and determined their chromaticity coordinates. Their X-ray luminescence and scintillation decay characteristics have been determined for the first time under pulsed electron beam excitation. The electron excitation dissipation processes in the cesium and rubidium compounds are shown to be similar. We discuss the origin of the emission bands in the mixed vanadates and their potential application areas.

Using solid-state reactions and a combination of carbothermal reduction-nitridation with solgel processing, we have synthesized a number of oxynitride phases: Eu2+-doped Ca-sialons. We have measured the pulsed cathodoluminescence spectra of the synthesized powders under pulsed electron beam excitation and determined their emission parameters, including temporal emission characteristics.