0000000000013691
AUTHOR
O. Fedchenko
Bulk spin polarization of magnetite from spin-resolved hard x-ray photoelectron spectroscopy
Physical review / B 104(4), 045129 (1-10) (2021). doi:10.1103/PhysRevB.104.045129
Transmission electron microscopy investigation of oxidation of (110)NiAl single crystal with wedge-shaped profile
Abstract Low energy electron diffraction (LEED), high resolution transmission electron microscopy (HRTEM), energy-dispersive X-ray (EDX), and electron energy loss spectroscopy (EELS) investigations of oxidation processes in (110)NiAl single crystal of wedge like shape, i.e., on the sample’s areas of different thickness, were carried out. It was found that in the result of several cycles of ion etching, annealing and oxidation the upper layer of (110)NiAl is enriched with Ni. With the increase of Ni concentration from 50 to 100 at. %, the stoichiometry of the near surface area changes and the new phases of Ni3Al and Ni with Al doping are formed one after another. Up to Ni content of 75 at. %…
Spinovo rozlisena time-of-flight k-reozlisena fotoemissia Ir-- Kompletny fotoemissny experiment.
Ultramicroscopy 183, 19 - 29 (2017). doi:10.1016/j.ultramic.2017.06.025
Momentum-resolved photoelectron absorption in surface barrier scattering on Ir(111) and graphene/Ir(111)
Physical review / B 96(15), 155108 (2017). doi:10.1103/PhysRevB.96.155108
Suppression of the vacuum space-charge effect in fs-photoemission by a retarding electrostatic front lens
Review of scientific instruments 92(5), 053703 (2021). doi:10.1063/5.0046567
Design for a high resolution electron energy loss microscope.
International audience; An electron optical column has been designed for High Resolution Electron Energy Loss Microscopy (HREELM). The column is composed of electron lenses and a beam separator that are placed between an electron source based on a laser excited cesium atom beam and a time-of-flight (ToF) spectrometer or a hemispherical analyzer (HSA). The instrument will be able to perform full field low energy electron imaging of surfaces with sub-micron spatial resolution and meV energy resolution necessary for the analysis of local vibrational spectra. Thus, noncontact, real space mapping of microscopic variations in vibrational levels will be made possible. A second imaging mode will al…
Rashba splitting of the Tamm surface state on Re(0001) observed by spin-resolved photoemission and scanning tunneling spectroscopy
Physical review research 2(1), 013296 (2020). doi:10.1103/PhysRevResearch.2.013296
Band structure tuning of Heusler compounds: Spin- and momentum-resolved electronic structure analysis of compounds with different band filling
Physical review / B 103(5), 054407 (2021). doi:10.1103/PhysRevB.103.054407
Néel Vector Induced Manipulation of Valence States in the Collinear Antiferromagnet Mn 2 Au
The coupling of real and momentum space is utilized to tailor electronic properties of the collinear metallic antiferromagnet Mn2Au by aligning the real space Neel vector indicating the direction o...
Temperature-Dependent Change of the Electronic Structure in the Kondo Lattice System $YbRh_{2}Si_{2}$
Seminar, Deutschland; Journal of physics / Condensed matter 00(00), 1-20 (2021). doi:10.1088/1361-648X/abe479
Site-specific atomic order and band structure tailoring in the diluted magnetic semiconductor (In,Ga,Mn)As
Physical review / B 103(7), 075107 (1-13) (2021). doi:10.1103/PhysRevB.103.075107
Hosting of surface states in spin–orbit induced projected bulk band gaps of W(1 1 0) and Ir(1 1 1)
Journal of physics / Condensed matter 29(25), 255001 - (2017). doi:10.1088/1361-648X/aa7173
4D texture of circular dichroism in soft-x-ray photoemission from tungsten
Brief treatment and crisis intervention 21(1), 013017 (2019). doi:10.1088/1367-2630/aaf4cd
Magneto-optical properties of two-layer film systems based on Fe and Cr
The results of the investigation of two-layer Fe/Cr systems using the magneto-optical Kerr effect (MOKE) are presented in this paper. The samples were obtained by thermal evaporation in a vacuum with a thickness of individual layers from 2 nm to 50 nm. It was found that the presence of the Cr layer significantly affects the values of the coercivity and the Kerr angle. At a substrate temperature of 450 K, the value of the coercivity is almost half that of the same sample obtained at room temperature of the substrate. In addition, the influence of the order of deposition of layers, as well as the effect of a thin gold protective layer on the parameters measured by the Kerr method, is shown. …
Narrow-band pulsed electron source based on near-threshold photoionization of Cs in a magneto-optical trap
The newly developed method of time-of-flight (ToF) momentum microscopy was used to analyse the cold electron emission from a Cs 3D magneto-optical trap (MOT). Three-step resonant photoionization was implemented via two intermediate states (6P3/2 pumped with 852 nm laser and 7S1/2 with 1470 nm) and a tuneable femtosecond Ti:sapphire laser for the final ionization step. The magnetic field of the MOT is switched off during the photoionization step. The natural bandwidth of the fs-laser is reduced to 4 meV using optical spectral filters. Precise tuning of the photon energy makes it possible to observe the transition regime between direct photoemission into the open continuum and field induced i…
Growth and defect studies of CdTe particles
The paper reports the epitaxial growth of cadmium telluride (CdTe) particles by thermal deposition on cleaved planes of (001)NaCl and (001)KBr. Using high resolution transmission electron microscopy and electron diffraction it was shown that CdTe particles could have different orientation and phase (cubic or hexagonal) depending on the substrate temperature. Their most common defects are twins and stacking faults.
Multidimensional photoemission spectroscopy—the space-charge limit
New journal of physics 20(3), 033004 - (2018). doi:10.1088/1367-2630/aaa262
Direct 3D mapping of the Fermi surface and Fermi velocity.
Time-of-flight momentum microscopy is developed. It enables direct three-dimensional mapping of the topology of the Fermi surface, identification of electron and hole pockets, and quantification of Fermi velocity as a function of wavevector.
Extraction dynamics of electrons from magneto-optically trapped atoms
Pulsed photoionization of laser-cooled atoms in a magneto-optical trap (MOT) has the potential to create cold electron beams of few meV bandwidths and few ps pulse lengths. Such a source would be highly attractive for the study of fast low-energy processes like coherent phonon excitation. To study the suitability of MOT-based sources for the production of simultaneously cold and fast electrons, we study the photoionization dynamics of trapped Cs atoms. A momentum-microscope-like setup with a delay-line detector allows for the simultaneous measurement of spatial and temporal electron distributions. The measured patterns are complex, due to the Lorentz force inducing spiral trajectories. Ray-…
High-resolution hard-x-ray photoelectron diffraction in a momentum microscope—the model case of graphite
New journal of physics 21(11), 113031 - (2019). doi:10.1088/1367-2630/ab51fe
Emitter-site specificity of hard x-ray photoelectron Kikuchi-diffraction
New journal of physics 22(10), 103002 (1-13) (2020). doi:10.1088/1367-2630/abb68b
Time-of-flight photoelectron momentum microscopy with 80–500 MHz photon sources: electron-optical pulse picker or bandpass pre-filter
Journal of synchrotron radiation 28(6), 1891 - 1908 (2021). doi:10.1107/S1600577521010511