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dr hab. Ryszard Zdyb

Zakład

Zakład Fizyki Powierzchni i Nanostruktur

Stanowisko:

prof. nadzw.

Kontakt:

pokój: 254
telefon: (081) 537-61-48
e-mail: ryszard.zdyb@umcs.pl

Specjalność naukowa:

fizyka

Funkcje pełnione w IF UMCS:

Dyrektor Instytutu Fizyki 2017-

Publikacje: Ukryj abstrakty

  1. R. Zdyb, A. Pavlovska, E. Bauer, Strain engineering of magnetic anisotropy in thin ferromagnetic films, Journal of Physics: Condensed Matter, 21(), 2009, 314012 (1-6)

  2. R. Zdyb, T. O. Mentes, A. Locatelli, M. A. Nino, E. Bauer, Magnetization and structure of ultrathin Fe films, Physical Review B, 80(), 2009, 184425 (1-9)

  3. Zdyb, R., Influence of substarte morphology on Pb growth, Applied Surface Science, 254(), 2008, 4408-4413

  4. Zdyb, R., Growth of Pb on Si(335) surface, Journal of Non-Crystalline Solids, 354(), 2008, 4176-4180

  5. Skrobas, K. Zdyb, R. Kisiel, M. Jałochowski, M., Band structure of In chains on Si(335)-Au, Materials Science-Poland, 26(), 2008, 55-61

  6. Zdyb, R. Bauer, E., Coexistence of ferromagnetism and paramagnetism in a ferromagnetic monolayer, Physical Review Letters, 100(), 2008, 155704 (1-4)

  7. Zdyb, R., Quantum and finite size effects in ultrathin Fe films, Abstract of 14-th International Conference on Solid Films and Surfaces, (), 2008, 135-136

  8. Zdyb, R., Pb cluster array on Si(111)-(7x7) surface, Liverpool, Abstract of 25-th European Conference on Surface Science, , (), 2008, 81-82

  9. Zdyb, R. Bauer, E., Spin reorientation transition in ultrathin Fe films on W(110), Abstract of 6-th international workshop on LEEM-PEEM, (), 2008, 35

  10. Skrobas, K. Zdyb, R. Jałochowski, M., Struktura elektronowa klasterów Pb i In na powierzchni Si(111)-(7x7), Kraków, II Krajowa Konferencja Nanotechnologii, Książka streszczeń, (), 2008,

  11. Nita, P. Stępniak, A. Jałochowski, M. Skrobas, K. Zdyb, R. Krawiec, M., Rekonstrukcje In na powierzchni Si(335)-Au,Kraków, II Krajowa Konferencja Nanotechnologii, Książka streszczeń, (), 2008,

  12. Jałochowski, M. Stróżak, M. Zdyb, R., Klastery atomów Pb na powierzchni Si(111)-(7x7), Zakopane, Streszczenia V Seminarium STM/AFM, wyd. IF UJ, Kraków 2008, (), 2008, P-I-13

  13. Kisiel, M. Skrobas, K. Zdyb, R. Mazurek, P. Jałochowski, M., Pb chains on ordered Si(335) surface, Physics Letters A, 364(), 2007, 152-156

  14. Kisiel, M. Jalochowski, M. Zdyb, R., Morphology and electronic structure of submonolayer Pb on Si(111)-(6x6)Au, Physics Letters A, 357(2), 2006, 141-145

    Abstract:
    The electronic structure and the morphology of Pb adsorbed on the Si(111)-(6 x 6)Au substrate in the coverage range from 0.025 up to 1 monolayer are investigated with ultraviolet photoelectron spectroscopy (UPS) and scanning tunneling microscopy (STM). The UPS measurements reveal two distinct peaks in the spectra. Correlation with the STM images allows us to associate one of them with single Pb atoms. The second peak emerges at coverage of 0.075 ML and is identified as a localized quantum well state. An evolution of these states as a function of the Pb coverage is determined. (c) 2006 Elsevier B.V. All rights reserved.

  15. Zdyb, R. Pavlovska, A. Jalochowski, M. Bauer, E., Self-organized Fe nanostructures on W(110), Surface Science, 600(8), 2006, 1586-1591

    Abstract:
    The magnetic domain structure of Fe wires, ribbons and islands with different shapes that have been prepared under ultra high vacuum conditions on W(I 10) are studied with spin polarized low energy electron microscopy. The dimensions of the nanostructures, which are of the order of tens and hundreds of nm, can be controlled by the temperature at which they are produced, by the average Fe coverage and by the substrate morphology. The domain structure of the nanostructures depends on their shape and is determined by the competition between magnetoelastic.. shape and magnetocrystalline anisotropies. (c) 2006 Elsevier B.V. All rights reserved.

  16. Bauer, E. Belkhou, R. Cherifi, S. Hertel, R. Heun, S. Locatelli, A. Pavlovska, A. Zdyb, R. Agarwal, N. Wang, H., Microscopy of mesoscopic ferromagnetic systems with slow electrons, Surface and Interface Analysis, 38(12-13), 2006, 1622-1627

    Abstract:
    Mesoscopic ferromagnetic systems are not only of practical interest for high density recording and storage devices but also as models of cooperative phenomena in low dimensions. The magnetization distribution in such systems is studied in this paper by X-ray Magnetic Circular Dichroism Photo Emission Microscopy (XMCDPEEM), using thin rectangular and ring-shaped patterned Co films and by Spin-Polarized Low Energy Electron Microscopy (SPLEEM), using epitaxial Fe nanostructures. Copyright (C) 2006 John Wiley & Sons, Ltd.

  17. Kisiel, M. Skrobas, K. Zdyb, R. Jalochowski, M., Band structure of Au monoatomic chains on Si(335) and Si(557) surfaces, Optica Applicata, 35(3), 2005, 449-455

    Abstract:
    The electronic band structure of the Si(557) and Si(335) surfaces covered with monoatomic Au chains produced in UHV conditions, is investigated in detail by. angle-resolved photoelectron spectroscopy (ARPES), especially for the surface state bands near the Fermi energy. The ARPES spectra in the plane parallel to step edges for Si(557)-Au vicinal surface show strongly dispersive electron energy bands, characteristic of one-dimensional structure. The band dispersion is also calculated within tight-binding model, with two adjustable coupling parameters t(1) and t(2), for the first and second neighbors along the chains, respectively, and compared with that determined from the photoemission experiment. The scanning tunneling microscopy (STM) imaging and reflection high energy electron diffraction (RHEED) studies enabled us to determine atomic chain separation and its internal structure. The study shows that the structural anisotropy of these surfaces induces highly anisotropic electronic structure.

  18. Zdyb, R. Pavlovska, A. Locatelli, A. Heun, S. Cherifi, S. Belkhou, R. Bauer, E., Imaging low-dimensional magnetism with slow electrons, Applied Surface Science, 249(1-4), 2005, 38-44

    Abstract:
    Two aspects of low-dimensional magnetism are discussed: the spin-dependent quantization effects in perfect two-dimensional single crystal layers and the magnetic domain structure of submicron magnetic patterns. Both require high lateral resolution and surface sensitivity. This is provided by spin- polarized low energy electron microscopy (SPLEEM) and X-ray magnetic circular dichroism photoemission electron microscopy (XMCDPEEM). (c) 2004 Elsevier B.V. All rights reserved.

  19. Zdyb, R. Locatelli, A. Heun, S. Cherifi, S. Belkhou, R. Bauer, E., Nanomagnetism studies with spin-polarized low-energy electron microscopy and x-ray magnetic circular dichroism photoemission electron microscopy, Surface and Interface Analysis, 37(2), 2005, 239-243

    Abstract:
    The spin reorientation transition (SRT) of ultrathin Fe-Co alloy films on an Au(111) surface and the magnetic/structural phase transition of epitaxial MnAs films on a GaAs(100) surface are studied by two electron microscopic techniques with very high surface sensitivity, i.e. spin-polarized to energy electron microscopy (SPLEEM) and x-ray magnetic circular dichroism photoemission electron microscopy (XMCDPEEM), combined with low-energy electron microscopy (LEEM) and low- energy electron diffraction (LEED), respectively. A new SRT mechanism is found and the interrelation between ferromagnetism and structure is elucidated. Copyright (C) 2005 John Wiley Sons, Ltd.

  20. Jalochowski, M. Strozak, M. Zdyb, R., Optical recognition of structural and electronic transformation of Pb ultrathin films, Journal of Physics-Condensed Matter, 16(39), 2004, S4345-S4352

    Abstract:
    In this study, the transformation of ultrathin Pb film on a Si(111)-(7 x 7) surface from amorphous-like to crystalline state is examined at low temperatures during the film growth by measuring the differential reflectance (DR) DeltaR/R, as a function of film thickness. The experiments were performed under ultrahigh vacuum conditions in the visible and infrared spectral range. The determined imaginary part of the Pb dielectric function changes steeply at the critical thickness of the film of about 5 monoatomic Pb(111) layers. High energy electron diffraction (RHEED) and scanning tunnelling microscopy (STM) studies revealed a film with fine granular morphology before the structural transition and a well ordered epitaxial layer after the transformation. The variation of the optical (AC) conductivity was compared with DC electrical conductance data. We show that the DR technique can be efficiently used to characterize structural and electronic changes in ultrathin metallic films.

  21. Zdyb, R. Jalochowski, M. Strozak, M., Quantum size effect in absorption of low energy electrons in Pb layers, Vacuum, 74(2), 2004, 217-222

    Abstract:
    Absorption of low-energy electrons in Pb ultrathin layers grown on a Si(111)-(6 x 6)Au substrate has been measured as a function of the incident electron energy and of the film thickness. The thickness-dependent curves of the current revealed two distinct features. One of them is associated with the quantum size effect and showed the characteristic oscillatory behavior with the periodicity determined by the film thickness. The other, independent of the film thickness, was attributed to the bulk band structure of Pb. On the basis of the changes in the quantum size oscillations peak position as a function of the transmitted electron energy, and of the layer thickness, the electronic band structure of Pb 8-20eV above the vacuum level has been determined in the GammaL direction. (C) 2004 Elsevier Ltd. All rights reserved.

  22. Jalochowski, M. Strozak, M. Zdyb, R., Reflectance anisotropy during growth of Pb nanowires on well ordered Si(335) surface, Applied Surface Science, 211(1-4), 2003, 209-215

    Abstract:
    Ultrathin Pb films on Si(3 3 5) deposited at temperatures ranging from 105 to 305 K are investigated by optical reflectance method, scanning tunneling microscopy, and reflection high energy electron diffraction. From the reflectance data for light with photon energy of 0.6 eV, the imaginary part of the Pb dielectric function epsilon(2)(Pb) is determined. For films with coverages below about 2 monoatomic layers (ML), independent on the substrate temperature, epsilon(2)(Pb) linearly increases with the average film thickness. For larger Pb coverages, it strongly depends on the deposition temperature. The observed variation of the dielectric function is correlated with structural and topographic transitions of Pb ultrathin films growing on Si(3 3 5) surface. The origin of the optical anisotropy as a consequence of self-assembling of Pb nanowires on well ordered Si(3 3 5) substrate is discussed. (C) 2003 Elsevier Science B.V. All rights reserved.

  23. Man, K. L. Zdyb, R. Huang, S. F. Leung, T. C. Chan, C. T. Bauer, E. Altman, M. S., Growth morphology, structure, and magnetism of ultrathin Co films on W(111), Physical Review B, 67(18), 2003, art. no.-184402

    Abstract:
    The growth morphology, structure, and magnetism of ultrathin Co films on the W(111) surface are studied with conventional and spin polarized low energy electron microscopy and diffraction and first principles total energy calculations. Pseudo-layer- by-layer growth of thick pseudomorphic (ps) Co films is observed at 380 K, while Stranski-Krastanov growth and transformation to a (6x6) closed-packed structure are observed at higher temperatures. On the basis of the calculations, only one ps Co monolayer is expected to be thermodynamically stable against three-dimensional island formation. Calculations also indicate that the magnetic moment on Co atoms at the interface is reduced due to strong hybridization with the substrate, but remains non-zero even for the single ps monolayer. Metastable ps Co/W(111) is found experimentally to be ferromagnetically ordered at 380 K when film thickness exceeds 7.6 ps ML. Although only in-plane magnetization is observed, substrate atomic steps have a strong influence on the magnetization easy axis and magnetic domain structure, which suggests that the in- plane magnetocrystalline anisotropy is weak.

  24. Zdyb, R. Bauer, E., Magnetic domain structure and spin-reorientation transition in ultrathin Fe-Co alloy films, Physical Review B, 67(13), 2003, art. no.-134420

    Abstract:
    The evolution of the magnetic domain structure with the thickness of Fe1-xCox alloy films deposited at room temperature on epitaxial Au(111) films is studied for xless than or equal to0.3 by spin-polarized low-energy electron microscopy. In contrast to pure Fe films that show no out-of-plane magnetization small amounts of Co are sufficient to induce strong perpendicular magnetization below three monolayers with a pronounced striped domain structure. A reorientation transition to in-plane magnetization is found.

  25. Jalochowski, M. Strozak, M. Zdyb, R., Anomalous optical absorption in ultrathin Pb films, Physical Review B, 66(20), 2002, art. no.-205417

    Abstract:
    Ultrathin Pb films on Si(111)-(6x6)-Au deposited at 100 K are investigated by scanning tunneling microscopy, reflection high energy electron diffraction, and optical reflectance methods. From the reflectance data for light with a photon energy from 0.5 to 3 eV, the imaginary part of the Pb dielectric function epsilon(Pb) is determined. For films with a thickness of 12 ML, the Pb epsilon(Pb) vs photon energy resembles that expected for a bulk material. At smaller coverages the absorption spectrum shows anomalous, sharp optical structures. These structures are identified as strongly enchanced optical transitions characteristic of bulk materials. Simultaneously, a reduction of the free-electron Drude absorption is observed. This phenomenon is explained in terms of reduced electron screening. Our findings supply evidence of a bulklike electron band structure in ultrathin films and nanoparticles of Pb deposited on Si(111)-(6x6)Au.

  26. Zdyb, R. Bauer, E., Spin-dependent quantum size effects in the electron reflectivity of ultrathin ferromagnetic crystals, Surface Review and Letters, 9(3-4), 2002, 1485-1491

    Abstract:
    We have studied the spin-dependent quantum size effects in the reflection of 0-20 eV electrons from 2-10-ML-thick Fe microcrystals grown in situ on a W(110) surface in a spin- polarized low energy electron microscope. The goal is to obtain a better understanding of the magnetic ( "asymmetry") image contrast and of the limits of spin polarization devices based on the quantum size contrast. The contrast is interpreted in terms of the band structure and, of the spin-dependent inelastic mean free path. For the figure of merit of spin polarization devices, an upper limit of 5 x 10(-2) is obtained.

  27. Zdyb, R. Bauer, E., Spin-resolved unoccupied electronic band structure from quantum size oscillations in the reflectivity of slow electrons from ultrathin ferromagnetic crystals, Physical Review Letters, 88(16), 2002, art. no.-166403

    Abstract:
    The spin-dependent reflectivity of electrons with energies between 0 and 20 eV from Fe single crystals 2-8 monolayers thick on a W(110) surface is studied by spin-polarized low energy electron microscopy. The quantum size oscillations in the reflectivity are analyzed in a similar manner as in photoemission of ground state electrons, yielding the spin- resolved unoccupied state band structure of Fe in the GammaN direction in the energy range studied.

  28. Zdyb, R. Strozak, M. Jalochowski, M., Gold-induced faceting on Si(533) surface studied by RHEED, Vacuum, 63(1-2), 2001, 107-112

    Abstract:
    Reflection high energy electron diffraction (RHEED) technique was used to study the Si(5 3 3) surface. On the samples cut 14.42 degrees off the (1 1 1) plane in the [2 (1) over bar (1) over bar] direction, a submonolayer of Au up to 0.628 monolayer (ML) was deposited. Bare Si(5 3 3) surfaces after cleaning in ultrahigh vacuum conditions by short flashing up to about 1500 K did not show a long range older on the macroscopic scale. Upon increasing the coverage of Au, the surface transformed gradually into a flat and perfectly ordered Si(5 3 3) plane at a coverage equal to 0.275 ML, and split into a hill-and-valley structure consisting of (1 1 1) and (1 1 5 5) facets at 0.50 ML of Au, and a combination of (1 1 1) and (3 1 1) facets at 0.628 ML of Au. The crucial role of single atom chains of Au formed on the (1 1 1) terraces is experimentally verified and discussed. It was shown that these chains stabilize the facets and allow the creation of a large macroscopic Si(5 3 3) plane. We suggest that this mechanism can also be operative in the case of Si(1 1 5 5) and Si(3 1 1) planes. (C) 2001 Elsevier Science Ltd. All rights reserved.

  29. Duden, T. Zdyb, R. Altman, M. S. Bauer, E., Micromagnetic and microcrystalline structure of ultrathin Co layers on W single crystal surfaces, Surface Science, 480(3), 2001, 145-152

    Abstract:
    The magnetic domain structure and the microcrystalline structure of ultrathin Co layers on W(1 1 0), W(1 0 0) and W(1 1 1) surfaces are studied with low energy electron microscopy with and without spin-polarization with the goal to shed some light on the importance of the various parameters which determine the micromagnetic structure. (C) 2001 Elsevier Science B.V. All rights reserved.

  30. Jalochowski, M. Strozak, M. Zdyb, R., One-dimensional structures on Si(111) observed by RHEED, Thin Solid Films, 306(2), 1997, 224-227

    Abstract:
    A vicinal Si(111) surface covered with a sub-monolayer amount of Au has been studied by reflection high energy electron diffraction (RHEED). At the coverage equal to 0.20 ML of Au, the RHEED pattern showed a reconstruction in the form of regularly distributed monoatomic steps. In order to determine the shape of the surface unit cell, several RHEED patterns obtained within a wide range of the electron incident angle were recorded and analyzed. The surface was composed of flat Si(111) terraces separated by single Si(111) steps. This surface was identified as an ideal Si(755) facet with Au atoms that form quasi-one-dimensional chains running along a Si[1(1) over bar0$] azimuth. Regularly spaced steps were stable within the investigated range of temperatures from 100 to 470 K. (C) 1997 Elsevier Science S.A.

  31. Jalochowski, M. Strozak, M. Zdyb, R., Gold-induced ordering on vicinal Si(111), Surface Science, 375(2-3), 1997, 203-209

    Abstract:
    A vicinal Si(111) surface covered with a sub-monolayer amount of Au has been studied by RHEED. For a sample misoriented by 8.46 degrees towards the [(1) over bar (1) over bar 2] azimuthal direction at a coverage equal to 0.20 ML of Au, the RHEED pattern showed a regular distribution of monoatomic steps with the staircase width equal to 18.88+/-0.33 Angstrom. Au- induced order was identified with a (755) facet of Si. Regularly spaced steps were stable within the investigated range of temperatures from 130 to 470 K. Upon further increase of the Au-coverage the periodicity was disturbed and al a coverage of about 0.50 ML of Au onset of (root 3 x root)R30 degrees reconstruction was visible. (C) 1997 Elsevier Science B.V.

  32. Jalochowski, M. Strozak, M. Zdyb, R., Gold-induced one-dimensional ordering on vicinal Si(111), Vacuum, 48(3-4), 1997, 273-275

    Abstract:
    Behaviour of a sub-monolayer Au-coverage on the vicinal Si(111) has been studied by RHEED. For the sample misoriented by 8.46 degrees towards the [<(11)over bar 2>] azimuthal direction at the coverage equal to 0.20 ML of Au, the RHEED pattern showed almost perfect distribution of the monoatomic Si(111) steps with the staircase width equal to 18.52 +/- 0.66 Angstrom. Au- induced order was identified with the (755) facet of Si with a one-dimensional chains of Au. Upon further increase of the Au deposition this regular distribution was gradually disturbed and at the coverage of about 0.50 ML of Au onset of an (root 3 x root 3)R 30 degrees reconstruction was visible. (C) 1997 Elsevier Science Ltd.


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