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Related papers: Hybrid Models of Step Bunching

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We report numerical results for two models of vicinal motion. The first, LW, aims at crystal evaporation when the detachment from steps is slow [Liu and Weeks, PRB 57, 23 (1998) 14891]. The source of destabilization is electromigration…

Materials Science · Physics 2010-05-06 Diana Staneva , Bogdan Ranguelov , Vesselin Tonchev

The classification of bunching of straight steps on vicinal crystal surfaces identifies two types according to the behavior of the minimal step-step distance in the bunch lmin with increasing the number of steps N in it. In the B1-type lmin…

Materials Science · Physics 2012-05-15 Vesselin Tonchev

We report for the first time the observation of bunching of monoatomic steps on vicinal W(110) surfaces induced by step up or step down currents across the steps. Measurements reveal that the size scaling exponent {\gamma}, connecting the…

The step bunching instability is studied in three models of step motion defined in terms of ordinary differential equations (ODE). The source of instability in these models is step-step attraction, it is opposed by step-step repulsion and…

Materials Science · Physics 2016-04-20 Anna Krasteva , Noriko Akutsu , Vesselin Tonchev

We formulate a new (1+1)D step model of potentially unstable vicinal growth that we call "C+ - C-" model and study the step bunching process in it. The basic assumption is that the equilibrium adatom concentrations on both sides of the step…

Chemical Physics · Physics 2007-05-23 Bogdan Ranguelov , Vesselin Tonchev , Hiroo Omi , Alberto Pimpinelli

A sublimating vicinal crystal surface can undergo a step bunching instability when the attachment-detachment kinetics is asymmetric, in the sense of a normal Ehrlich-Schwoebel effect. Here we investigate this instability in a model that…

Statistical Mechanics · Physics 2015-05-18 Marian Ivanov , Vladislav Popkov , Joachim Krug

Concerted experimental and numerical studies of step bunching on vicinal crystal surfaces resulting from step-down electromigration of partially charged adatoms, confirmed the theoretical prediction of scaling dependence of the minimal…

This work provides a ground for a quantitative interpretation of experiments on step bunching during sublimation of crystals with a pronounced Ehrlich-Schwoebel (ES) barrier in the regime of weak desorption. A strong step bunching…

Materials Science · Physics 2009-11-10 Joachim Krug , Vesselin Tonchev , Stoyan Stoyanov , Alberto Pimpinelli

We devise a new 1D atomistic scale model of vicinal growth based on Cellular Automaton. In it the step motion is realized by executing the automaton rule prescribing how adatoms incorporate into the vicinal crystal. Time increases after…

Materials Science · Physics 2017-09-13 F. Krzyżewski , M. Załuska-Kotur , A. Krasteva , H. Popova , V. Tonchev

We approach the old-standing problem of vicinal crystal surfaces destabilized by step-down and step step-up currents from a unified modelling viewpoint with focus on both the initial and the intermediate stages of the instability. We…

We review the studies on the scaling of the minimal step-step distance lmin in the bunch with the bunch size N, l_min~N^(-{\gamma}). We build our retrospective around the different values of the exponent {\gamma} obtained from models and…

Materials Science · Physics 2016-12-01 Katarzyna Siewierska , Vesselin Tonchev

We study step bunching under conditions of attachment/detachment limited kinetics in the presence of a deposition or sublimation flux, which leads to bunch motion. Analysis of the discrete step dynamics reveals that the bunch velocity is…

Statistical Mechanics · Physics 2009-11-11 V. Popkov , J. Krug

We study the step bunching process in three different 1D step flow models and obtain scaling relations for the step bunches formed in the long times limit. The first one was introduced by S.Stoyanov [Jap. J.Appl. Phys. 29, (1990) L659] as…

Materials Science · Physics 2012-05-15 Bogdan Ranguelov , Vesselin Tonchev , Chaouqi Misbah

The coexistence of step bunching and step meandering remains contradictory in the understanding of the unstable step-flow growth. Considered separately, the two instabilities have generated rich but largely independent modeling traditions.…

We study current-induced step bunching and wandering instabilities with subsequent pattern formations on vicinal surfaces. A novel two-region diffusion model is developed, where we assume that there are different diffusion rates on terraces…

Materials Science · Physics 2009-11-10 T. Zhao , J. D. Weeks

Bunching of steps at the surface of growing crystals can be induced by both directions of the driving force: step up and step down. The processes happen in different adatom concentrations and differ in character. In this study we show how…

Materials Science · Physics 2020-01-24 Hristina Popova , Filip Krzyżewski , Magdalena Załuska-Kotur , Vesselin Tonchev

We study the evolution of step bunches on vicinal surfaces using a thermodynamically consistent step-flow model that (i) circumvents the quasistatic approximation that prevails in the literature by accounting for the dynamics of adatom…

Materials Science · Physics 2021-10-04 Lucas Benoit--Maréchal , Michel E. Jabbour , Nicolas Triantafyllidis

By carrying out Monte Carlo simulations,we study step bunching during solution growth. For simplicity, we consider a square lattice, which represents a diffusion field in a solution, and express the diffusion of atoms as the hopping of…

Materials Science · Physics 2015-05-20 Masahide Sato

We studied the step dynamics during sublimation and growth in the presence of electromigration force acting on the adatoms. In the limit of fast surface diffusion and slow kinetics of atom attachment-detachment at the steps we formulate a…

Chemical Physics · Physics 2009-11-13 Bogdan Ranguelov , Stoyan Stoyanov

We study vicinal crystal surfaces with the terrace-step-kink model on a discrete lattice. Including both a short-ranged attractive interaction and a long-ranged repulsive interaction arising from elastic forces, we discover a series of…

Condensed Matter · Physics 2009-12-31 V. B. Shenoy , Shiwei Zhang , W. F. Saam
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