dr inż. Yevgen Melikhov

Zakład Biosystemów i Miękkiej Materii (ZBiMM)
Pracownia Fizyki Płynów Złożonych (PFPZ)
stanowisko: specjalista
telefon: (+48) 22 826 12 81 wew.: 161
pokój: 311
e-mail: ymelik

Doktorat
2001-12-20Preisach Model Formalism as a Magnetic Tool for Material Investigation 
promotor -- dr Ivan Tomas, Charles University, Prague, Czech Republic
1408 
Ostatnie publikacje
1.Hussain M., Misbah-ul-Islam , Meydan T., Cuenca J.A., Melikhov Y., Mustafa G., Murtaza G., Jamil Y., Microwave absorption properties of CoGd substituted ZnFe2O4 ferrites synthesized by co-precipitation technique, CERAMICS INTERNATIONAL, ISSN: 0272-8842, DOI: 10.1016/j.ceramint.2017.12.145, Vol.44, No.6, pp.5909-5914, 2018

Streszczenie:

A series of co-precipitated Zn1-xCoxGdyFe2-yO4 spinel ferrites (x = 0.0-0.5, y = 0.00-0.10) sintered at 1000 degrees C were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), vibrating sample magnetometery (VSM) and microwave cavity perturbation (MCP). XRD patterns and FTIR spectra reveal formation of the spinel phase along with few traces of GdFeO3 second phase. The lattice constant decreases with an increasing amount of CoGd ions due to the segregation of Gd3+ on the grain boundaries and due to replacement of lager Zn2+ ions with smaller Co2+ ions. SEM shows grain size to decrease with the increase of CoGd contents due to grain growth inhibition by the second phase. VSM results show remanence and saturation magnetization to exhibit an increasing trend due to Co substitution on octahedral sites and presence of a second phase. The coercivity increases with the increase of CoGd contents due to anisotropic nature of Co. MCP shows the complex magnetic permeability to increase with CoGd concentration while the complex permittivity decreases.

Słowa kluczowe:

Spinel ferrites, Magnetization, Permittivity, Permeability

Afiliacje autorów:

Hussain M.-Bahauddin Zakariya University, Multan (PK)
Misbah-ul-Islam -Bahauddin Zakariya University, Multan (PK)
Meydan T.-Cardiff University (UK)
Cuenca J.A.-Cardiff University (UK)
Melikhov Y.-other affiliation
Mustafa G.-Bahauddin Zakariya University, Multan (PK)
Murtaza G.-Bahauddin Zakariya University, Multan (PK)
Jamil Y.-Department of Physics, University of Agriculture, Faisalabad (PK)
40p.
2.Demchenko I.N., Syryanyy Y., Melikhov Y., Nittler L., Gladczuk L., Lasek K., Cozzarini L., Dalmiglio M., Goldoni A., Konstantynov P., Chernyshova M., X-ray photoelectron spectroscopy analysis as a tool to assess factors influencing magnetic anisotropy type in Co/MgO system with gold interlayer, SCRIPTA MATERIALIA, ISSN: 1359-6462, DOI: 10.1016/j.scriptamat.2017.10.006, Vol.145, pp.50-53, 2018

Streszczenie:

X-ray photoelectron spectroscopy (XPS) studies of Au/Co/Au(0.3 nm)/MgO and Au/Co/MgO systems were conducted in order to monitor the electronic structure modification at Co/MgO interface with/without gold interlayer. A detailed analysis of Co 2p states revealed that the amount of minor oxygen contribution at Co/MgO interface decreased after the Au interlayer was added. The obtained XPS results together with density functional theory (DFT) allowed explanation of the increase of surface anisotropy energy in the sample with the gold interlayer in terms of (i) noble and transitional metal d-d orbital hybridization; (ii) interfacial Co 3d and O 2p; and (iii) interface imperfection.

Afiliacje autorów:

Demchenko I.N.-Institute of Physics, Polish Academy of Sciences (PL)
Syryanyy Y.-Institute of Physics, Polish Academy of Sciences (PL)
Chernyshova M.-Institute of Plasma Physics and Laser Microfusion (PL)
Melikhov Y.-other affiliation
Nittler L.-Institute of Physics, Polish Academy of Sciences (PL)
Gladczuk L.-Institute of Physics, Polish Academy of Sciences (PL)
Lasek K.-Institute of Physics, Polish Academy of Sciences (PL)
Cozzarini L.-Elettra-Sincrotrone Trieste S.C.p.A. (IT)
Dalmiglio M.-Elettra-Sincrotrone Trieste S.C.p.A. (IT)
Goldoni A.-Elettra-Sincrotrone Trieste S.C.p.A. (IT)
Konstantynov P.-Institute of Physics, Polish Academy of Sciences (PL)
35p.
3.Chernyshova M., Malinowski K., Melikhov Y., Kowalska-Strzęciwilk E., Czarski T., Wojeński A., Linczuk P., Krawczyk R.D., Study of the optimal configuration for a Gas Electron Multiplier aimed at plasma impurity radiation monitoring, Fusion Engineering and Design, ISSN: 0920-3796, DOI: 10.1016/j.fusengdes.2018.03.031, Vol.136, pp.592-596, 2018

Streszczenie:

For the purpose of monitoring the level of plasma impurity (especially tungsten) and its distribution reconstruction at tokamaks (ITER in particular), a Soft X-Ray (SXR) tomographic diagnostics based on Gas Electron Multiplier (GEM) detectors with energy discrimination has been extensively considered for a while. Coupled with advanced electronics, GEM detectors offer excellent time and space resolution, as well as a charge spectrum from which the SXR photon spectrum can be deconvolved. In addition, they are less subjected to a neutron damage as compared to standard semiconductor diodes. This contribution highlights the latest studies supporting the development of such diagnostics focusing on laboratory tests to examine: (a) the impact of GEM holes geometry on the properties and distribution of the electron avalanche; (b) the effect of the high rate photon flux on GEM foil performance; and (c) the optimal electric field distribution.

Słowa kluczowe:

Nuclear instruments for hot plasma diagnostics, X-ray detectors, Electron multipliers (gas), Micropattern gaseous detectors (MSGC; GEM; THGEM; RETHGEM; MHSP; MICROPIC; MICROMEGAS; InGrid; etc.)

Afiliacje autorów:

Chernyshova M.-Institute of Plasma Physics and Laser Microfusion (PL)
Malinowski K.-Institute of Plasma Physics and Laser Microfusion (PL)
Melikhov Y.-other affiliation
Kowalska-Strzęciwilk E.-Institute of Plasma Physics and Laser Microfusion (PL)
Czarski T.-Institute of Plasma Physics and Laser Microfusion (PL)
Wojeński A.-Warsaw University of Technology (PL)
Linczuk P.-Institute of Plasma Physics and Laser Microfusion (PL)
Krawczyk R.D.-Warsaw University of Technology (PL)
30p.
4.Demchenko I.N., Melikhov Y., Syryanyy Y., Zaytseva I., Konstantynov P., Chernyshov M., Effect of argon sputtering on XPS depth-profiling results of Si/Nb/Si, JOURNAL OF ELECTRON SPECTROSCOPY AND RELATED PHENOMENA, ISSN: 0368-2048, DOI: 10.1016/j.elspec.2017.09.009, Vol.224, pp.17-22, 2018

Streszczenie:

Ultrathin Si/Nb/Si trilayer is an excellent example of a system for which dimensionality effects, together with other factors like type of a substrate material and growth method, influence strongly its superconducting properties. This study offers some important insights into experimental investigation of density of states of such a system with the aim to identify an electronic structure of the interface as a function of niobium layer thickness. For that, two Si/Nb/Si trilayers with 9.5 and 1.3 nm thick niobium layer buried in amorphous silicon were studied using high-resolution (HR) XPS depth-profile techniques. Strong influence of sputtering was observed, which resulted in severe intermixture of Si and Nb atoms. Nevertheless, a sharp top interface and metallic phase of niobium were detected for the thicker layer sample. On the contrary, a Nb-rich mixed alloy at top interface was observed for the thinner layer sample.

Słowa kluczowe:

High-resolution X-ray photoelectron spectroscopy, XPS, Si/Nb/Si, NbSi, Depth profiling

Afiliacje autorów:

Demchenko I.N.-Institute of Physics, Polish Academy of Sciences (PL)
Melikhov Y.-other affiliation
Syryanyy Y.-Institute of Physics, Polish Academy of Sciences (PL)
Zaytseva I.-Institute of Physics, Polish Academy of Sciences (PL)
Konstantynov P.-Institute of Physics, Polish Academy of Sciences (PL)
Chernyshov M.-Institute of Plasma Physics and Laser Microfusion (PL)
25p.
5.Chernyshova M., Czarski T., Malinowski K., Melikhov Y., Kasprowicz G., Kowalska-Strzęciwilk E., Linczuk P., Wojeński A., Krawczyk R.D., 2D GEM based imaging detector readout capabilities from perspective of intense soft x-ray plasma radiation, REVIEW OF SCIENTIFIC INSTRUMENTS, ISSN: 0034-6748, DOI: 10.1063/1.5039278, Vol.89, No.10, pp.10G106-1-5, 2018

Streszczenie:

A detecting system based on the Gas Electron Multiplier (GEM) technology is considered for tokamak plasma radiation monitoring. In order to estimate its capabilities in processing and recording intense photon flux (up to similar to 0.1 MHz/mm(2)), the imaging effectiveness of GEM detectors was tested with different patterned anode planes (i. e., different signal readouts): a simple hexagonal readout structure and three structures with interconnected electrodes (XY square, XY rectangular, and UXV). It was found that under intense photon flux, all the readouts fail to account for a considerable amount of the incoming signals due to mostly photon position determination ambiguity and overlapped signals. Analysis of the signals that can be used to determine photon position and energy unambiguously showed that the UXV readout structure is more effective among the readouts with interconnected electrodes. Along with similar spatial resolution and accuracy, the UXV based layout could be considered as a quite promising base of the interconnected anode electrodes configuration, keeping in mind that the photon rate capability has to be improved for the final application.

Afiliacje autorów:

Chernyshova M.-Institute of Plasma Physics and Laser Microfusion (PL)
Czarski T.-Institute of Plasma Physics and Laser Microfusion (PL)
Malinowski K.-Institute of Plasma Physics and Laser Microfusion (PL)
Melikhov Y.-other affiliation
Kasprowicz G.-Warsaw University of Technology (PL)
Kowalska-Strzęciwilk E.-Institute of Plasma Physics and Laser Microfusion (PL)
Linczuk P.-Institute of Plasma Physics and Laser Microfusion (PL)
Wojeński A.-Warsaw University of Technology (PL)
Krawczyk R.D.-Warsaw University of Technology (PL)
25p.

Prace konferencyjne
1.Demchenko I.N., Melikhov Y., Konstantynov P., Ratajczak R., Barcz A., Guziewicz E., Resonant Photoemission Spectroscopy Study on the Contribution of the Yb 4f States to the Electronic Structure of ZnO, ACTA PHYSICA POLONICA A, ISSN: 0587-4246, DOI: 10.12693/APHYSPolA.133.907, Vol.133, No.4, pp.907-909, 2018

Streszczenie:

The electronic structure of Yb implanted ZnO has been studied by the resonant photoemission spectroscopy. The contribution of the Yb 4f partial density of states is predominant at binding energy about 7.5 and approximate to 11.7 eV below the VB maximum. At photon energy about 182 eV the multiplet structure around 11.7 eV shows the strongest resonance that corresponds to the I-1 multiplet which is almost exclusively responsible for this resonance, while H-3 and F-3 states are responsible for the resonance around 7.5 eV. It was also found that the Yb 4f partial density of states distribution shows some similarity to Yb2O3.

Afiliacje autorów:

Demchenko I.N.-Institute of Physics, Polish Academy of Sciences (PL)
Melikhov Y.-other affiliation
Konstantynov P.-Institute of Physics, Polish Academy of Sciences (PL)
Ratajczak R.-National Centre for Nuclear Research (PL)
Barcz A.-Institute of Physics, Polish Academy of Sciences (PL)
Guziewicz E.-Institute of Physics, Polish Academy of Sciences (PL)
15p.