Research concentrates on diffusion and phase transitions of clean surfaces and surfaces covered with adsorbates and thin layers. The study of the interaction of the adsorbates with solid surfaces with respect to morphology, geometric and electronic structure is carried out via real space imaging techniques (STM, PEEM) as well as theoretical modeling.

DYNAMICS OF NANOSTRUCTURES

The control of kinetic parameters in thin metal film or nanostructures growth on semiconductors is of utmost importance for the ability to design novel nanoscale structures with novel electronic or catalytic properties.
The main program of our group in this field is the study of the unusual growth mode of uniform height

Fig 1: kMC simulation of the nucleation on Pb mesa. The Mesa grows on the step on the Si substrate - the left part of the island is 4 layer thick, the right one is 5 layer thick. Due the QSE effect have both halves with different thickness also different physical and chemical properties (ie. surface diffusion of critical cluster size which both leads to difference in probability of the nucleation)

islands discovered in Pb/Si, which was related to the electronic Quantum Size Effect (QSE). In addition to these energetic reasons provided by QSE, there is also the question of kinetics, i.e., how atoms diffuse and how new critical clusters forms. Interesting are also different mode of island growth, observed at different temperatures and different heights of island. We develop analytical models of nucleation and growth of nanostructures and kinetic Monte Carlo simulations of processes, which are driven by QSE.

Fig 2: kMC simulation of the nucleation on the terrace during the deposition of Mg on W. The total amount deponed on the empty W is 20ML. The simulated area is periodical.

Besides the microscopic models of new structure evolution, we study also ordering processes and spreading of ordered phase of adatoms on substrate surface, in particular case of Au/Si system.

MEMBERS

 doc. Zdenek Choj, Martin Mašín PhD, Zdenka Chromcová (borned Kuntová) PhD

COOPERATION

Prof. Michael C. Tringides 

Prof. Talat S. Rahman

Prof. Tapio Ala-Nissila

PUBLICATIONS

[1] Structures of metal nanoparticles adsorbed on MgO(001). I. Ag and Au; Ferrando R; Rossi G; Levi AC, et al. ; JOURNAL OF CHEMICAL PHYSICS 130(2009)174702

[2] Structures of metal nanoparticles adsorbed on MgO(001). II. Pt and P; Goniakowski J; Jelea A; Mottet C, et al. ; JOURNAL OF CHEMICAL PHYSICS 130(2009)174703

[3] Melting of core-shell Ag-Ni and Ag-Co nanoclusters studied via molecular dynamics simulations ; Kuntova Z; Rossi G; Ferrando R ; PHYSICAL REVIEW B 77(2008)205431

[4] Height-dependent barriers and nucleation in quantum size effect growth; Kuntova Z; Tringides MC; Chvoj Z ; PHYSICAL REVIEW B 78(2008)155431

[5] Monte carlo simulations of growth modes of Pb nanoislands on Si(111) surfac; Kuntova Z; Chvoj Z; Tringides MC, et al. ; EUROPEAN PHYSICAL JOURNAL B 64(2008) 61-66

[6] Bilayer-ring second-layer nucleation morphology in Pb/Si(111)-7x7;Kuntova Z; Hupalo M; Chvoj Z, et al. ; PHYSICAL REVIEW B 75(2007)205436

[7] Non-classical kinetics processes and morphologies in QSE driven growth in Pb/Si(111); Kuntova Z; Hupalo M; Chvoj Z, et al. ; SURFACE SCIENCE 600(2006) 4765-4770

[8] Limitations of the thermodynamic, Gibbs-Thompson analysis of nanoisland decay;Kuntova Z; Chvoj Z; Sima V, et al. ; PHYSICAL REVIEW B 71(2005) 125415

[9] Single atom diffusion of Pb on a Si(111)-7x7 surface ; Kuntova Z; Jelinek P; Chab V, et al.; SURFACE SCIENCE 566(2004) 130-136