A5080313202- Magnetic properties of thin films
- Electron and X-Ray Spectroscopy Techniques
- Metallic Glasses and Amorphous Alloys
- Rare-earth and actinide compounds
- Metal and Thin Film Mechanics
- Magnetic Properties and Applications
- X-ray Spectroscopy and Fluorescence Analysis
- Topological Materials and Phenomena
- ZnO doping and properties
- Advanced Materials Characterization Techniques
- Advanced Electron Microscopy Techniques and Applications
- Iron-based superconductors research
- Advanced Condensed Matter Physics
- Electronic and Structural Properties of Oxides
- Ga2O3 and related materials
- Crystallography and Radiation Phenomena
- Material Properties and Applications
- Quantum, superfluid, helium dynamics
- GaN-based semiconductor devices and materials
- Advanced X-ray Imaging Techniques
- Advanced Sensor and Energy Harvesting Materials
- Cold Atom Physics and Bose-Einstein Condensates
- Neural Networks and Reservoir Computing
- Adhesion, Friction, and Surface Interactions
- Multiferroics and related materials
Sumy State University
2011-2025
Johannes Gutenberg University Mainz
2023-2025
Goethe University Frankfurt
2022
Kremenchuk Mykhailo Ostrohradskyi National University
2020
Altermagnets are an emerging elementary class of collinear magnets. Unlike ferromagnets, their distinct crystal symmetries inhibit magnetization while, unlike antiferromagnets, they promote strong spin polarization in the band structure. The corresponding unconventional mechanism time-reversal symmetry breaking without electronic spectra has been regarded as a primary signature altermagnetism but not experimentally visualized to date. We directly observe structure altermagnetic RuO 2 by...
Using x-ray photoelectron diffraction (XPD) and angle-resolved photoemission spectroscopy, we study intensity changes related to in the geometric electronic structure kagome metal CsV_{3}Sb_{5} upon transition an unconventional charge density wave (CDW) state. The XPD patterns reveal presence of a chiral atomic CDW phase. Furthermore, using circularly polarized x-rays, have found pronounced nontrivial circular dichroism angular distribution valence band phase, indicating chirality structure....
Imaging energy filters in photoelectron microscopes and momentum use spherical fields with deflection angles of 90°, 180° even 2 × 180°. These instruments are optimized for high resolution, exhibit image aberrations when operated transmission mode at medium resolution. Here, a new approach is presented bandpass-filtered imaging real or reciprocal space using an electrostatic dodecapole asymmetric electrode array. In addition to energy-dispersive beam deflection, this multipole allows...
Soft X-ray momentum microscopy of crystalline solids is a highly efficient approach to map the photoelectron distribution in four-dimensional (E,k) parameter space over entire Brillouin zone. The fixed sample geometry eliminates any modulation matrix element otherwise caused by changing angle incidence. We present new endstation at soft branch beamline I09 Diamond Light Source, UK. key component large single hemispherical spectrometer combined with time-of-flight analyzer behind exit slit....
The influence of the addition Bi to dilute ferromagnetic semiconductor (Ga,Mn)As on its electronic structure as well magnetic and structural properties has been studied. Epitaxial (Ga,Mn)(Bi,As) layers high perfection have grown using low-temperature molecular-beam epitaxy. Post-growth annealing samples improves their increases hole concentration in layers. Hard X-ray angle-resolved photoemission spectroscopy reveals a strongly dispersing band Mn-doped layers, which crosses Fermi energy is...
The results of analysis literature and own on the phase composition, electrophysical magnetoresistive properties film based granular alloys Co Ag or Au.As between systems Fe Au much in common, then this work can be seen as a continuation [1], although we observed significant withdrawal these two groups materials structural-phase state, causing some change properties.The increase value temperature coefficient resistance (Co) at сСо ≥ 26 at.% strain 70 at.%.It is concluded that GMR...
Bulk ${\mathrm{EuPd}}_{2}{\mathrm{Si}}_{2}$ show a temperature-driven valence transition of europium from $\ensuremath{\sim}+2$ above 200 K to $\ensuremath{\sim}+3$ below 100 K, which is correlated with shrinking by approximately 2% the tetragonal crystal lattice along two $a$-axes. Due this interconnection between and electronic degrees freedom influence strain in epitaxial thin films particularly interesting. Ambient x-ray diffraction (XRD) confirms an relationship on MgO(001) out-of plane...
Hard x-ray angle-resolved photoemission spectroscopy reveals the momentum-resolved band structure in an epitaxial ${\mathrm{Mn}}_{2}\mathrm{Au}$(001) film capped by a 2-nm-thick ferromagnetic permalloy layer. By magnetizing capping layer, exceptionally strong exchange bias aligns N\'eel vector accordingly. Uncompensated interface Mn magnetic moments ${\mathrm{Mn}}_{2}\mathrm{Au}$ were identified as origin of using circular dichroism combination with photoelectron emission microscopy. Using...
We present the results of hard x-ray angle-resolved photoemission spectroscopy and diffraction measurements performed on high-quality single crystals valence transition compound ${\mathrm{EuPd}}_{2}{\mathrm{Si}}_{2}$ for temperatures $25\phantom{\rule{4.pt}{0ex}}\text{K}\ensuremath{\le}T\ensuremath{\le}300$ K. At low temperatures, we observe a Eu $4f$ $v=2.5$, which decreases to $v=2.1$ above around ${T}_{V}\ensuremath{\approx}160$ The experimental numbers resulting from an evaluation...
The strong electric field between the sample and extractor is core of cathode lenses a pivotal determinant high resolution. Nevertheless, fields in range 3-8 kV/mm can be source complications. Local enhancement at sharp edges or microscopic protrusions cleaved samples may result emission flashovers. Moreover, slow background electrons are drawn into microscope column, where they contribute to space charge effects. A novel front lens configuration, optimized through ray-tracing simulations,...
Using x-ray photoelectron diffraction (XPD) and angle-resolved photoemission spectroscopy, we study intensity changes related to in the geometric electronic structure kagome metal CsV$_3$Sb$_5$ upon transition an unconventional charge density wave (CDW) state. The XPD patterns reveal presence of a chiral atomic CDW phase. Furthermore, using circularly polarized x-rays, have found pronounced non-trivial circular dichroism angular distribution valence band phase, indicating chirality...
Hard X-ray angle-resolved photoemission spectroscopy reveals significant alterations in the valence band states of EuPd$_2$Si$_2$ at a temperature $T_V$, where Eu ions undergo temperature-induced crossover from magnetic Eu$^{2+}$ state to low-temperature valence-fluctuating state. The introduction small amounts Au on Pd lattice sites and Ge Si sites, respectively, results decrease $T_V$ emergence an antiferromagnetic low temperatures without fluctuations. It has been proposed that boundary...
Spin-polarized two-dimensional electron gases (2DEGs) are of particular interest for functional oxide electronics applications. The redox-created 2DEG residing on the strontium titanate, SrTiO$_3$ (STO), side a europium monoxide (EuO)/SrTiO$_3$ (001) interface is expected to be significantly spin-polarized due proximity strong ($7\,\mu_B/f.u.$) Heisenberg ferromagnet EuO. We apply magnetic circular dichroism in angular distribution (MCDAD) photoemitted electrons investigate whether and how...
Photoelectron diffraction (PED) is a powerful and essential experimental technique for resolving the structure of surfaces with sub-angstrom resolution. In high energy regime, researchers in angle-resolved photoemission spectroscopy (ARPES) observe modulating patterns attributed to X-ray-PED (XPD) effects. This accompanied by other challenges such as low cross-sections, significant photon momentum transfer, non-negligible phonon scattering. Overall, XPD not only an advantageous approach but...
Driving quantum materials out-of-equilibrium makes it possible to generate states of matter inaccessible through standard equilibrium tuning methods. Upon time-periodic coherent driving electrons using electromagnetic fields, the emergence Floquet-Bloch enables creation and control exotic phases. In transition metal dichalcogenides, broken inversion symmetry within each monolayer results in a non-zero Berry curvature at K K$^{\prime}$ valley extrema, giving rise chiroptical selection rules...
This article discusses the influence of geometry mesoscopic structures based on Ni3Pt nanoparticles magnetothermal characteristics to maximize magnetocaloric response.Nanostructured samples in form arrays nanocylinders and nanowires were made using a combination electron-beam lithography electrochemical deposition methods.It was determined that change from nanostructured objects contributes an increase effect operating temperature range.