Vladimír Cháb

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Group subject:

Structure and dynamics on surfaces with atomic resolution


Name and Curriculum vitae of contact person:

Vladimír Cháb (Ing., CSc.)

Affiliation:

Institute of Physics, Academy of Sciences of the Czech Republic

Position - Vicehead of Dept. of Thin Films, Scientist in Charge at Materials Science Beamline, Elettra, Trieste

Fields of scientific activity:

• Surface Physics - Photoelectron Spectroscopy, Low Energy Electron Diffraction, PhotoElectron Emission Microscopy, Scanning Tunneling Microscopy, Scanning Tunneling Spectroscopy - structure and electronic structure of semiconductor surfaces, initial stages of metal/semiconductor interface formation, surface diffusion on semiconductor surfaces.

• Materials Science - laser treatment of semiconductor surfaces, application of synchrotron radiation for industrial sample, dynamics of phase transitions induced by short laser pulses on semiconductor surfaces, non-equilibrium processes, interaction of gases with steel and other metals important in the industry.

• The supervisor of 10 diploma thesis and 7 PhD thesis, two from Italy.

• Publications: Author or co-author of more than 200 scientific publications (more than 150 were published in international journals) to which more than 300 references appeared in the literature.

Selected study stays abroad:

• 1978 Chalmers University, Gothenberg, Sweden, P.-O. Nilsson

• 1984, 1986 Fritz-Haber Institut MPG, Berlin, Germany, A. M. Bradshaw

• 1988, 1989 IGV KFA Juelich Germany, H. Bonsel

• 1990 Sinctrotrone Trieste, Trieste, Italy, K. C. Prince

• 1993 Fritz-Haber Institut MPG, Berlin, Germany, A. M. Bradshaw

• 1995 University 6-7, Paris, France, C. Cohen

Selected solved projects:

Design and construction of the Czech materials science beamline at source of synchrotron radiation source Elettra, Trieste Italy. 2 EC and 6 Czech grants successfully finished.

Selected related publications from last 5 years:

• B.Ressel, J. Slezák, K.C. Prince and V. Cháb: Quantized valence states of the Pb/Si(111) mosaic phase, Physical Review B 66, 035325-1- 035325-4(2002)

• L Ottaviano, B. Ressel, C. Di Teodoro, G. Profeta S. Santucci, V. Cháb, K. C. Prince: Short-range order in two-dimensional binary alloy, Physical Review B 67, 045401-1-045401-9 (2003)

• P. Mutombo, V. Cháb: Theoretical STM images of Cu atoms on a Si(111) surface, Surface Science 532-535, 645-649 (2003)

• P.Shukrinov, P. Mutombo, V. Cháb, K. C. Prince: Co-adsorption of Cu and Pb atoms on the Si(111)-7x7 surface: interface formation, Surface Science 532-535, 650-654 (2003)

• P. Jelínek, M. Ondřejček, J. Slezák, V. Cháb: Experimental and theoretical studies of single Pb atom dynamicsin one Si(111)-7x7 unit cell, Surface Science 544, 339-347 (2003)

Group members:

Vlad. Cháb, Zdeněk Chvoj, Pingo Mutombo, Pavel Jelínek, Martin Mašín, Martin Švec, Zdenka Kuntová, Martin Ondráček, Viktor Dudr, Vladimír Matolín, Karel Mašek, Kateřina Veltruská, Iva Matolínová, Václav Nehasil (FMP- CU).

Main Research Subjects:

The first subject is preparation and study of semiconductor surfaces and metal-semiconductor interfaces on the atomic and the nanoscopic scale. Reconstruction, relaxation and dynamics on a monocrystalline surface after a deposition of metal atoms are monitored as a function of temperature and coverage. The corresponding changes in the local density of states are studied using different scanning probe spectroscopies. The surface electronic structure is calculated with CRYSTAL 98 code based on the DFT variation of Hartree-Fog approximation. Similarly, surface diffusion is calculated analytically at coverage lower than one monolayer at the non-eqiulibrium conditions and simulated with a Kinetic Monte Carlo tool.

The second subject is experimental study of the electron density of states, chemical composition and chemical state of surfaces and interfaces with photoelectron spectroscopy at the source of synchrotron radiation "Elettra", Trieste, Italy. Photoelectron diffraction-one of the operating mode- allows a direct determination of nearest neighbours arrangement of a chosen atom or molecule on a surface.

The third subject is the experimental study of the structure sensitive nanoscale surface reactivity of metallic systems. The surface structure is investigated by means of electron diffraction methods (RHEED, LEED, XPD), the reactivity by electron (XPS, UPS, AES), ion (SIMS, ISS) and molecular (TDS) spectroscopy.

Selected Specific Equipment:

Variable temperature Omicron AFM/STM UHV system equipped with the LEED/AES tools. In-situ metal deposition with two FOCUS water cooled evaporators enables a preparation of bimetalic layers.

Photoelectron spectrometer connected to the beamline (20eV - 1000 eV) at Elettra. with overall resolution 2000. Preparation chamber with fast enter lock, SPALEED, evaporators. Operating modes: ESCA, CFS, CIS.

X-ray photoelectron spectrometer Omicron EA125, X-ray/UV/XPD photoelectron spectrometer PHOIBOS 150, 1 - 1000 amu Perkin Elemer SIMS, SPECS ErLEED 1000, Auger electron spectrometer Staib Ins. DESA 100, 30keV RHEELS/RHEED Staib Ins.

Additional recent selected publications by group members:

• M. Šnábl, M.Ondřejček, V.Cháb, Z.Chvoj, W.Stenzel, H.Conrad, A.M.Bradshaw: Surface Diffusion of K on Pd(111): Coverage Dependence of the Diffusion Coefficient Determined with the Boltzmann-Matano Method, J. Chem. Phys. 108, 4212 (1998)

• Z.Chvoj, V.Chá b,H.Conrad: Surface Diffusion on a lattice with two non-equivalent adsorption sites: repulsive interaction, Surf. Sci. 426, 8-25 Impact Factor: 2.1800 (1999)

• J.Slezák, P.Mutombo, V.Cháb: Temperature study of phase coexistence in the system Pb on an Si(111) surface, Surf. Sci. 454-456, 584-590. Impact Factor: 2.3850 (2000)
• J.Slezák, M.Ondřejček, Z.Chvoj, V.Cháb, H.Conrad, S.Heun, Th.Schmidt, B.Ressel, K.C.Prince: Surface diffusion of Au on Si(111): A microscopic study, Phys. Rev. B 61, 16121-16128 (2000)

• K.C.Prince, I.Ulrych, M.Peloi, B.Ressel, V.Cháb, C.Crotti, C.Comicioli: Core-level photoemission from graphite, Phys. Rev. B 62, 1-3. Impact Factor: 3.0080 (2000)

• R.Vašina, V.Kolaříkk, P.Doležel, M.Mynář, M.Vondráček, V.Cháb, J.Slezák, C.Comicioli, K.C.Prince: Mechanical design aspects of a soft X-ray plane grating monochromator, Nuclear Instruments and Methods in Physics Research A 467-468, 561-564 (2001)

• J. Křivánek, J. Hořejš, V. Cháb, G. Tromba: Bude se synchrotronové záření využívat i v radiodiagnostice ? Česká radiologie 57, No. 2. pp 75-78, Vydává Česká lékařská společnost J. E. Purkyně (2003)

• N. Tsud, K. Veltruská and V. Matolín: Pd interaction with reduced thin film alumina: XPS and ISS study, J.Catalysis, 204, 372 (2001).

N. Tsud, S. Fabík, V. Dudr, M. Vondráček, V. Cháb, V. Matolín, K.C. Prince: Interfacial reconstruction in the system Pb/Ag(1 1 0), Surf. Sci, 542, 112 (2003).
© 2005