Investigation local switching and self-organization effects on non-polar cuts of lithium niobate

The equipment of the Ural Center for Shared Use “Modern Nanotechnology” Ural Federal University was used. The research was made possible by Russian Science Foundation (Grant 14-12-00826)

Минералого-петрографические особенности и последовательность образования золотосурьмяных руд Удерейского месторождения (Красноярский край)

The article presents results of petrographic and mineralogical studies of gold-antimony ores of the Udereyskoe deposit and their concentration products. The main mineral associations of ores are characterized, mineral forms of occurrence are revealed, and distribution of Au, Pd, Ag is estimated. The paragenetic scheme of mineral formation sequence was clarified and supplemented. The important mineral forms of gold occurrence are goldbearing arsenopyrite and native gold (Au,Ag), as well as rare aurostibite AuSb2 and intermetallides such as antimony gold (Au,Sb), and palladium gold (Au,Pd). The revealed diversity of forms of noble metals and analysis of their relationships with associating sulfides and nonmetallic minerals indicate at least two contrasting early and late stages of ore genesis. Early quartz-pyrite and late pyrite, which are two stages of mineralization, are determened within the early stage. Three consecutive stages of mineralization are established in the late stage: quartz-stibnite, pyrite-stibnite-quartz, and pyrite-arsenopyrite-stibnite.Приводятся данные по петрографическим и минералогическим исследованиям исходных золотосурьмяных руд Удерейского месторождения и продуктов их обогащения. Охарактеризованы главные минеральные ассоциации руд, выявлены минеральные формы нахождения и оценено распределение Au, Pd, Ag. Уточнена и дополнена парагенетическая схема последовательности минералообразования. Важными минеральными формами нахождения золота являются преобладающие золотосодержащий арсенопирит и самородное золото (Au,Ag), а также редкие ауростибит AuSb2 и интерметаллиды – сурьмянистое золото (Au,Sb) и палладистое золото (Au,Pd). Выявленное многообразие форм нахождения благородных металлов и анализ их взаимоотношений с ассоциирующими сульфидами и нерудными минералами указывают на как минимум два контрастных этапа рудогенеза – ранний и поздний. В пределах раннего этапа выделены две стадии минерализации – ранняя кварц-пиритовая и поздняя колчеданная. В позднем этапе выделены три последовательные стадии минерализации: кварц-стибнитовая, пирит-стибнит-кварцевая и пирит-арсенопирит-стибнитовая

Spontaneous backswitching during tip-induced polarization reversal at lithium niobate non-polar surfaces

The equipment of the Ural Center for Shared Use “Modern nanotechnology” UrFU was used

Self-organized domain structure at non-polar cuts of lithium niobate as a result of local switching

The equipment of the Ural Center for Shared Use “Modern nanotechnology” Ural Federal University was used

Confocal Raman study of electric fields in lithium niobate single crystals

The research was made possible by Russian Science Foundation (Grant 19-72-10076). The equipment of the Ural Center for Shared Use “Modern nanotechnology” UrFU was used

Correlative confocal Raman and scanning probe microscopy in the ionically active particles of LiMn 2 O 4 cathodes

In this contribution, a correlative confocal Raman and scanning probe microscopy approach was implemented to find a relation between the composition, lithiation state, and functional electrochemical response in individual micro-scale particles of a LiMn 2 O 4 spinel in a commercial Li battery cathode. Electrochemical strain microscopy (ESM) was implemented both at a low-frequency (3.5 kHz) and in a high-frequency range of excitation (above 400 kHz). It was shown that the high-frequency ESM has a significant cross-talk with topography due to a tip-sample electrostatic interaction, while the low-frequency ESM yields a response correlated with distributions of Li ions and electrochemically inactive phases revealed by the confocal Raman microscopy. Parasitic contributions into the electromechanical response from the local Joule heating and flexoelectric effect were considered as well and found to be negligible. It was concluded that the low-frequency ESM response directly corresponds to the confocal Raman microscopy data. The analysis implemented in this work is an important step towards the quantitative measurement of diffusion coefficients and ion concentration via strain-based scanning probe microscopy methods in a wide range of ionically active materials. © 2019 by the authors

Chemical solution deposition of BiFeO3 films with layer-by-layer control of the coverage and composition

Chemical solution deposition of BiFeO3 thin films is one of the most commercially available techniques to produce large-scale low-cost coatings for further application in memory devices. In this contribution, we implemented piezoresponse force and conductive atomic force microscopies to study the layer-by-layer sol-gel deposition of BiFeO3 thin films focusing on the local phase distribution, morphology, piezoelectric response, and leakage current. The final properties of resulting thin films are found to be determined not only by the composition of the gel and crystallization step but by the gelation step as well. The drying temperature and treatment duration of the solution are shown to drastically influence the film coverage, which finally determines the morphology of the films and behavior of the crystallization process. © 2020 by the authors.Russian Science Foundation, RSF: 19-72-10076The research was funded by Russian Science Foundation, grant number 19-72-10076. The equipment of the Ural Center for Shared Use “Modern nanotechnology” UrFU was used