Spectromicroscopy of electronic phase separation in Kx_xFe2−y_{2-y}Se2_2 superconductor

Structural phase separation in A$_x$Fe$_{2-y}$Se$_2$ system has been studied by different experimental techniques, however, it should be important to know how the electronic uniformity is influenced, on which length scale the electronic phases coexist, and what is their spatial distribution. Here, we have used novel scanning photoelectron microscopy (SPEM) to study the electronic phase separation in K$_x$Fe$_{2-y}$Se$_2$, providing a direct measurement of the topological spatial distribution of the different electronic phases. The SPEM results reveal a peculiar interconnected conducting filamentary phase that is embedded in the insulating texture. The filamentary structure with a particular topological geometry could be important for the high T$_c$ superconductivity in the presence of a phase with a large magnetic moment in A$_x$Fe$_{2-y}$Se$_2$ materials.Comment: 14 pages,3 figure

Metallic phase in stoichiometric CeOBiS 2 revealed by space-resolved ARPES

Recently CeOBiS2 system without any fluorine doping is found to show superconductivity posing question on its origin. Using space resolved ARPES we have found a metallic phase embedded in the morphological defects and at the sample edges of stoichiometric CeOBiS2. While bulk of the sample is semiconducting, the embedded metallic phase is characterized by the usual electron pocket at X point, similar to the Fermi surface of doped BiS2-based superconductors. Typical size of the observed metallic domain is larger than the superconducting correlation length of the system suggesting that the observed superconductivity in undoped CeOBiS2 might be due to this embedded metallic phase at the defects. The results also suggest a possible way to develop new systems by manipulation of the defects in these chalcogenides with structural instability

Monatomic Excitation Temperature in Theoretical Study of Discharge with Liquid Non-Metallic (Tap Water) Electrodes in Air at Atmospheric Pressure

The discharge with liquid non-metallic electrodes under study is out of thermal equilibrium. From probe and micro-wave absorption measurements the electronic concentration has been evaluated. The spectral intensities of N2 and Oxygen triplet have been measured locally. In this work, we propose to compare the results of calculation with the experimental results for two hypotheses on the monatomic excitation temperature. The first is when we assume the monatomic excitation temperature close to heavy particle translational temperature and the second is when we assume the monatomic excitation temperature close to the electronic translational temperature

Determination of interatomic coupling between two-dimensional crystals using angle-resolved photoemission spectroscopy

Lack of directional bonding between two-dimensional crystals like graphene or monolayer transition metal dichalcogenides provides unusual freedom in selection of components for vertical van der Waals heterostructures. However, even for identical layers, their stacking, in particular the relative angle between their crystallographic directions, modifies properties of the structure. We demonstrate that the interatomic coupling between two two-dimensional crystals can be determined from angle-resolved photoemission spectra of a trilayer structure with one aligned and one twisted interface. Each of the interfaces provides complementary information and together they enable self-consistent determination of the coupling. We parametrize interatomic coupling for carbon atoms by studying twisted trilayer graphene and show that the result can be applied to structures with different twists and number of layers. Our approach demonstrates how to extract fundamental information about interlayer coupling in a stack of two-dimensional crystals and can be applied to many other van der Waals interfaces.Comment: This is a post-peer-review, pre-copyedit version of an article published in Nature Communications. The final authenticated version is available online at: http://dx.doi.org/10.1038/s41467-020-17412-

Archaeological sites as markers of Neopleistocene-Holocene hydrological system transformation in the Kurai and Chuya basins, Southeastern Altai: Results of geomorphological and geoarchaeological studies

Multidisciplinary studies using geomorphological, geoarchaeological, and geochronological approaches indicate contrasting environmental changes in Southeastern Altai, beginning in the Late Pleistocene. 29 new radiocarbon dates from the subaerial complex overlying Late Neopleistocene sediments in the high-altitude Kurai and Chuya basins confirm the degradation of a single ice-dammed reservoir in that area before the Early Holocene. In the first half of the Holocene, those basins were filled with isolated lakes. At the mouth of the Baratal River in the western Kurai basin, a reservoir with a water-level of at least 1480 m a.s.l. emerged ca 10–6.5 ka cal BP; whereas in the Chuya depression, numerous residual lakes existed at least 8 ka cal BP. Landslide- and moraine-dammed lakes between the depressions in the Chuya River valley existed until 7–3 ka cal BP, when they drained away. The state of preservation of in situ archaeological sites, their cultural affiliation, and their locations within the depressions and along the main Chuya valley attest to spatial and temporal changes in the hydrological system. This evolution in the second half of the Holocene did not entail major consequences for humans. All cataclysmic flood events took place (occurred) before 10–8 ka cal BP. © 2016 A.R. Agatova, R.K. Nepop, I.Y. Slyusarenko, V.S. Myglan, V.V. Barinov.Geomorphological studies, including radiocarbon dating, were supported by the Russian Foundation for Basic Research (Projects No. 15-05-06028 and 16-05-01035); archaeological and dendrochronological studies were supported by the Russian Science Foundation (Projects No. 14-50-00036 and 15-14-30011 respectively)

MANAJEMEN STRATEGI PELAKSANAAN KURIKULUM DALAM MEWUJUDKAN MADRASAH UNGGUL (Studi atas MA Muhammadiyah Kota Metro)

The public demand for quality or quality education is increasing. This phenomenon is at least influenced by two main factors namely; factors of globalization challenges and parents' awareness of the need for quality or quality education for their children. Another phenomenon that is not less interesting, today many schools are qualified and give more religious content became the first choice for parents, this condition is a challenge as well as opportunities for Senior High School  (MA) Muhammadiyah Metro City to rise from the shackles of dualism that is artificial and dualism management at once showcasing the various advantages that can be an attraction at the same time can invite public interest to make this institution as an option for the continuation of their children's education. This study aims to analyze management and strategy Implementation of the curriculum in realizing Senior High School (MA) Muhammadiyah Metro City Becomes a Superior School. This type of research is descriptive qualitative in which the data collection in this study was conducted by the method of observation, interview, and documentation study. Data that have been collected is then analyzed descriptively qualitative to then drawn conclusions. The results of this study will show that the management and implementation strategy of the curriculum in realizing Senior High School Muhammadiyah Metro City becomes a superior school. The results of this study recommend to management tiem in the implementation of the curriculum in realizing Senior High School Muhammadiyah Metro City Becomes a Superior School

Tricalcium Phosphate Ceramics Doped with Silver, Copper, Zinc, and Iron (III) Ions in Concentrations of Less Than 0.5 wt.% for Bone Tissue Regeneration

© 2016, Springer Science+Business Media New York.Novel materials with a variety of properties, such as biocompatibility, antibacterial activity, interconnected porosity, and functionalities combined in one, are required for regenerative medicine. Porous β-tricalcium phosphate (β-TCP) ceramics doped with Cu2+, Zn2+, Ag+, and Fe3+ ions in the concentrations of less than 0.5 wt.% were synthesized and investigated. The obtained samples were analyzed by the diversity of analytical tools. The structure, solubility, and antimicrobial properties of the porous ceramics are shown to be very sensitive to the presence and the type of the cationic substituent. It opens the way to manage structure and properties of the materials for bone tissue regeneration by co-doping of the initial matrix simultaneously with different types of substituent ions

Extremely small diffusion constant of Cs in multiwalled carbon nanotubes

The study of Cs intercalation process in multiwalled carbon nanotubes (MWNT) was done by cross-sectional scanning photoemission microscopy. It was found that Cs atoms initially deposited on the tips of aligned nanotubes diffused towards their roots. The evaluation of Cs diffusion constant for the MWNTs at room temperature was done from the Cs distribution measured along the axes of the tubes

Electronic structure of carbon nanotubes studied by photoelectron spectromicroscopy

The electronic structure of multiwalled carbon nanotubes aligned perpendicularly on a Si substrate was studied by means of photoelectron spectromicroscopy. The valence band and the C 1s spectra, measured systematically from spatially selected regions along the tube axes, were the fingerprint for lateral variations in the electron density of states and in the band bending, respectively. It was found that the tips have a larger density of states near the Fermi level than the sidewalls, whereas band bending, which would explain such a spectral difference, was not observed. It is suggested that the different density of states near the Fermi level is due to a larger dangling bond density at the tips

Археологические памятники как маркер перестройки неоплейстоцен-голоценовой гидросети Курайской и Чуйской впадин (Юго-Восточный Алтай): результаты геолого-геоморфологических и геоархеологических исследований

Multidisciplinary studies using geomorphological, geoarchaeological, and geochronological approaches indicate contrasting environmental changes in southeastern Altai beginning from the Late Pleistocene. Twenty-eight new radiocarbon dates from the subaerial complex overlying Late Neopleistocene sediments in the high-altitude Kurai and Chuya basins confi rm the degradation of a single ice-dammed reservoir in that area during the Early Holocene. In the first half of the Holocene, those basins were filled with isolated lakes. At the Baratal River mouth in the western Kurai basin, a reservoir with a water level of at least 1480 m a.s.l. emerged ca 10-6.5 ka BP, whereas in the Chuya depression, numerous residual lakes had existed at least 8 ka BP. Landslide- and morainedammed lakes between the depressions in the Chuya valley had existed until 7-3 ka BP, when they drained away. The preservation state of in situ archaeological sites, their cultural affiliation, and their location within the depressions and along the main Chuya valley attest to spatial and temporal changes of the hydrological system. This evolution occurred in the second half of the Holocene and did not entail major consequences for humans. © 2016 Siberian Branch of the Russian Academy of Sciences.Geomorphological studies, including radiocarbon dating, were supported by the Russian Foundation for Basic Research (Projects No. 15-05-06028 and 16-05-01035); archaeological and dendrochronological studies were supported by the Russian Science Foundation (Projects No. 14-50-00036 and 15-14-30011 respectively)