ОСОБЕННОСТИ ВЫРАЩИВАНИЯ НИЗКОДИСЛОКАЦИОННЫХ КРИСТАЛЛОВ ГЕРМАНИЯ БОЛЬШОГО ДИАМЕТРА МЕТОДОМ ЧОХРАЛЬСКОГО

Cz growth of large diameter Ge single crystals has been studied. The crystals have been grown from the melt with various shapes of the crystallization front. The formation of dislocation low angle boundaries (LAB) has been analyzed. We have analyzed the formation of LAB in the as−grown Ge crystals taking into account the actual distribution of thermal tension in the crystal in the presence of radial and axial heat sinks. The behavior LAB−forming dislocations in the thermal tension field has been considered. We have analyzed the migration of these dislocations in the sliding planes and specified possible dislocation aggregation planes. The best results have been obtained for crystals in which the crystallization front was slightly concave towards the crystal. Thus, we have observed a uniform distribution of dislocations. As a result of the analysis we have determined the thermal conditions for growth of LAB free ingots. Experiments confirmed the compliance of model representations with real crystal growth conditions, and we have obtained Ge single crystals with a diameter of100 mmand more, with a low dislocations density and free from LAB.Изучены процессы роста легированных монокристаллов германия большого диаметра, выращенных методом Чохральского из расплава с различной формой фронта кристаллизации (ФК). Проанализировано формирование дислокационных малоугловых границ (МУГ). Проведен анализ формирования МУГ в выращенных кристаллах германия с учетом реального распределения термических напряжений в кристалле при наличии как радиального, так и осевого теплоотвода. Рассмотрено поведение в поле термических напряжений дислокаций, из которых формировались МУГ. Проведен анализ движения этих дислокаций в плоскостях скольжения и выделены плоскости возможного скопления дислокаций. Наилучшие результаты достигнуты при выращивании кристаллов со слабовогнутым в кристалл ФК. Обнаружено однородное распределение дислокаций. В результате анализа выявлены тепловые условия получения слитков, свободных от МУГ. Проведены эксперименты, в результате которых подтверждено соответствие модельных представлений реальным условиям роста кристаллов и получены монокристаллы германия диаметром100 мми более с низкой плотностью дислокаций, свободные от МУГ

Performance and characterization of the FinEsuseAMS beamline at the MAX IV Laboratory

FinEstBeAMS (Finnish-Estonian Beamline for Atmospheric and Materials Sciences) is a multidisciplinary beamline constructed at the 1.5 GeV storage ring of the MAX IV synchrotron facility in Lund, Sweden. The beamline covers an extremely wide photon energy range, 4.5-1300 eV, by utilizing a single elliptically polarizing undulator as a radiation source and a single grazingincidence plane grating monochromator to disperse the radiation. At photon energies below 70 eV the beamline operation relies on the use of optical and thin-film filters to remove higher-order components from the monochromated radiation. This paper discusses the performance of the beamline, examining such characteristics as the quality of the gratings, photon energy calibration, photon energy resolution, available photon flux, polarization quality and focal spot size

Open questions in utility theory

Throughout this paper, our main idea is to explore different classical questions arising in Utility Theory, with a particular attention to those that lean on numerical representations of preference orderings. We intend to present a survey of open questions in that discipline, also showing the state-of-art of the corresponding literature.This work is partially supported by the research projects ECO2015-65031-R, MTM2015-63608-P (MINECO/ AEI-FEDER, UE), and TIN2016-77356-P (MINECO/ AEI-FEDER, UE)

POTENTIAL STRUCTURE OF DUST COMING OUT OF PROCESS OF COTTON REPRODUCTION

In this article the properties of dust allowing to retain waste of fibers, which are thrown out from production are researched and to bring concentration of dust in the atmosphere to normal level. For this purpose it was defined that dust and the form of powder, the chemical composition, density, a specific surface, stickiness and the strewing ability of dust were defined. It was claimed that it is necessary to carry out scientific-theoretical studies taking into account these parameters for the purpose of normal cleaning of particles of dust