Electronic structure of RE1-xAxMnO3 manganite films investigated by magnetic circular dichroism spectroscopy

Magnetic circular dichroism (MCD) spectroscopy was used to study the features of the electronic structure of an epitaxial La0.7Ca0.3MnO3 film in the range of 1.2 - 4 eV. The study of the temperature behavior of the MCD spectra made it possible to establish a correlation between the magnetooptical and transport properties of the sample. The data obtained were analyzed in comparison with MCD data for polycrystalline manganite films of various RE1-xAxMnO3 compositions. The MCD spectra of the films were compared with the spectra of the off-diagonal component of the permittivity tensor calculated from the data of the magneto-optical Kerr effect for films of the same composition. A unified set of ground and excited electronic states characteristic of RE1-xAxMnO3 manganites in the visible and near infrared ranges has been identified. These results are important for a qualitative theoretical description of the electronic structure of strongly correlated magnetic oxides.Comment: 5 figures, 2 table

Semiconducting Electronic Structure of the Ferromagnetic Spinel HgCr2Se4\mathbf{Hg}\mathbf{Cr}_2\mathbf{Se}_4 Revealed by Soft-X-Ray Angle-Resolved Photoemission Spectroscopy

We study the electronic structure of the ferromagnetic spinel $\mathrm{Hg}\mathrm{Cr}_2\mathrm{Se}_4$ by soft-x-ray angle-resolved photoemission spectroscopy (SX-ARPES) and first-principles calculations. While a theoretical study has predicted that this material is a magnetic Weyl semimetal, SX-ARPES measurements give direct evidence for a semiconducting state in the ferromagnetic phase. Band calculations based on the density functional theory with hybrid functionals reproduce the experimentally determined band gap value, and the calculated band dispersion matches well with ARPES experiments. We conclude that the theoretical prediction of a Weyl semimetal state in $\mathrm{Hg}\mathrm{Cr}_2\mathrm{Se}_4$ underestimates the band gap, and this material is a ferromagnetic semiconductor.Comment: 6+13 pages, 4+13 figure

Magnetic Semiconductors as Materials for Spintronics

From the various aspects of spintronics the review highlights the area devoted to the creation of new functional materials based on magnetic semiconductors and demonstrates both the main physical phenomena involved and the technical possibilities of creating various devices: maser, p-n diode with colossal magnetoresistance, spin valve, magnetic lens, optical modulators, spin wave amplifier, etc. Particular attention is paid to promising research directions such as ultrafast spin transport and THz spectroscopy of magnetic semiconductors. Special care has been taken to include a brief theoretical background and experimental results for the new spintronics approach employing magnetostrictive semiconductors-strain-magnetooptics. Finally, it presents top-down approaches for magnetic semiconductors. The mechano-physical methods of obtaining and features of the physical properties of high-density nanoceramics based on complex magnetic oxides are considered. The potential possibility of using these nanoceramics as an absorber of solar energy, as well as in modulators of electromagnetic radiation, is shown

Magnetic Semiconductors as Materials for Spintronics

From the various aspects of spintronics the review highlights the area devoted to the creation of new functional materials based on magnetic semiconductors and demonstrates both the main physical phenomena involved and the technical possibilities of creating various devices: maser, p-n diode with colossal magnetoresistance, spin valve, magnetic lens, optical modulators, spin wave amplifier, etc. Particular attention is paid to promising research directions such as ultrafast spin transport and THz spectroscopy of magnetic semiconductors. Special care has been taken to include a brief theoretical background and experimental results for the new spintronics approach employing magnetostrictive semiconductors—strain-magnetooptics. Finally, it presents top-down approaches for magnetic semiconductors. The mechano-physical methods of obtaining and features of the physical properties of high-density nanoceramics based on complex magnetic oxides are considered. The potential possibility of using these nanoceramics as an absorber of solar energy, as well as in modulators of electromagnetic radiation, is shown

Clothes of eurasian nomads at the scythian and saxon time (typology and terminology development)

В статье обобщен опыт систематизации, рассматриваются теоретические вопросы изучения костюма носителей археологических культур скифо-сакского мира, предлагаются: классификация костюма и типология отдельных категорий одежды, а также номинация составных элементов последней. Классификация костюма осуществляется на основе традиционного для отечественных этнографов подхода, согласно которому рассматриваемый комплекс подразделяется на головные уборы, наплечную и поясную одежду, а также обувь. При типологизации отдельных элементов одежды авторы руководствовались предполагаемыми особенностями кроя скифских облачений, номинация составных частей которых составлена с привлечением широкой массы разноплановых источников. Предложены новые типологии отдельных категорий одежды, созданные и применимые только при изучении одежды населения степной полосы Евразии в VIII-III вв. до . The article summarizes the experience of systemitizing, discusses the theoretical issues in the study of a garment worn by the representatives of Scythian and Saxon archaeological cultures. The article introduces to garment classification and typology of certain categories of clothes, as well as their constituent elements’ nomination. The classification is based on the traditional approach accepted by Russian ethnographers, according to which a garment under study is divided into hats, shoulder and waist clothes as well as shoes. In the process of the typology development the authors relied on the alleged peculiarities of the Scythian clothes cut. The nomination of its components was composed with reference to various sources. Thus, the authors propose a new typology of certain categories of clothes that could be developed and applied only in the study of clothes belonged to people of the steppe zone of Eurasia in VIII-III centuries BC

Strain-Magnetooptics in Single Crystals of CoFe₂O₄

The strain-magnetooptical properties of single crystals of the ferrimagnetic spinel CoFe2O4, which reflect a correlation between optical properties (magnetoabsorption and magnetoreflection) and magnetostriction, have been studied in the infrared spectral range. The conditions for the observation of the strain-magnetooptics are specified and physical mechanisms responsible for these effects in the spinel are explained

Genetically encoded BRET-activated photodynamic therapy for the treatment of deep-seated tumors

International audiencePhotodynamic therapy (PDT) is one of the most appealing photonic modalities for cancer treatment based on anticancer activity of light-induced photosensitizer-mediated reactive oxygen species (ROS), but a limited depth of light penetration into tissues does not make possible the treatment of deep-seated neoplasms and thus complicates its widespread clinical adoption. Here, we introduce the concept of genetically encoded bioluminescence resonance energy transfer (BRET)-activated PDT, which combines an internal light source and a photosensitizer (PS) in a singlegenetic construct, which can be delivered to tumors seated at virtually unlimited depth and then triggered by the injection of a substrate to initiate their treatment. To illustrate the concept, we engineered genetic NanoLuc-miniSOG BRET pair, combining NanoLuc luciferase flashlight and phototoxic flavoprotein miniSOG, which generates ROS under luciferase-substrate injection. We prove the concept feasibility in mice bearing NanoLuc-miniSOG expressing tumor, followed by its elimination under the luciferase-substrate administration. Then, we demonstrate a targeted delivery of NanoLuc-miniSOG gene, via tumor-specific lentiviral particles, into a tumor, followed by its successful elimination, with tumor-growth inhibition (TGI) coefficient exceeding 67%, which confirms a great therapeutic potential of the proposed concept. In conclusion, this study provides proof-of-concept for deep-tissue "photodynamic" therapy without external light source that can be considered as an alternative for traditional PDT

Dual Regioselective Targeting the Same Receptor in Nanoparticle-Mediated Combination Immuno/Chemotherapy for Enhanced Image-Guided Cancer Treatment

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Dual Regioselective Targeting the Same Receptor in Nanoparticle-Mediated Combination Immuno/Chemotherapy for Enhanced Image-Guided Cancer Treatment

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