arXiv subjects

Mikhail Khenner

Publications and source records attributed to Mikhail Khenner.

23 records · Page 2Linked to original sources

arXiv2015

Surface morphology coarsening in a nonlocal system

Direct comparison is made of the steady-sates and coarsening dynamics in a local system and its nonlocal generalization. The example system is the surface of a solid film in a strong electric field; the morphological evolution of the surface is described, in the long-wavelength approximation, by the amplitude PDE for the film height function. It is shown that the amplitude of the steady-state and the coarsening rate of the surface structure are very sensitive to the radius of the long-range interaction, and that both quantities increase as the radius decreases.

nlin.PS↗

arXiv2013

Analysis of a combined influence of substrate wetting and surface electromigration on a thin film stability and dynamical morphologies

A PDE-based model combining surface electromigration and wetting is developed for the analysis of morphological stability of ultrathin solid films. Adatom mobility is assumed anisotropic, and two directions of the electric field (parallel and perpendicular to the surface) are discussed and contrasted. Linear stability analyses of small-slope evolution equations are performed, followed by computations of fully nonlinear parametric evolution equations that permit surface overhangs. The results reveal parameter domains of instability for wetting and non-wetting films and variable electric field strength, nonlinear steady-state solutions in certain cases, and interesting coarsening behavior for strongly wetting films.

cond-mat.mtrl-sci↗

arXiv2011

Stability of a strongly anisotropic thin epitaxial film in a wetting interaction with elastic substrate

The linear dispersion relation for longwave surface perturbations, as derived by Levine et al. Phys. Rev. B 75, 205312 (2007) is extended to include a smooth surface energy anisotropy function with a variable anisotropy strength (from weak to strong, such that sharp corners and slightly curved facets occur on the corresponding Wulff shape). Through detailed parametric studies it is shown that a combination of a wetting interaction and strong anisotropy, and even a wetting interaction alone results in complicated linear stability characteristics of strained and unstrained films. PACS: 68.55.J, Morphology of films; 81.15.Aa, Theory and models of film growth; 81.16.Dn, Self-assembly.

cond-mat.mes-hall↗

arXiv2008

Comparative study of a solid film dewetting in an attractive substrate potentials with the exponential and the algebraic decay

We compare dewetting characteristics of a thin nonwetting solid film in the absence of stress, for two models of a wetting potential: the exponential and the algebraic. The exponential model is a one-parameter (r) model, and the algebraic model is a two-parameter (r,m) model, where r is the ratio of the characteristic wetting length to the height of the unperturbed film, and m is the exponent of h (film height) in a smooth function that interpolates the system's surface energy above and below the film-substrate interface at z=0. The exponential model gives monotonically decreasing (with h) wetting chemical potential, while this dependence is monotonic only for the m=1 case of the algebraic model. Linear stability analysis of the planar equilibrium surface is performed. Simulations of the surface dynamics in the strongly nonlinear regime (large deviations from the planar equilibrium) and for large surface energy anisotropies demonstrate that for any m the film is less prone to dewetting when it is governed by the algebraic model. Quasiequilibrium states similar to the one found in the exponential model (M. Khenner, Phys. Rev. B 77, 245445 (2008)) exist in the algebraic model as well, and the film morphologies are similar.

cond-mat.mtrl-sci↗

arXiv2004

Modeling of Oscillatory Driven Surface Evolution

A continuum (Mullins-type) model is formulated for the isotropic evolution of a solid surface on which the mass transport occurs by oscillatory surface diffusion. The time-space oscillations of diffusivity are assumed to be induced by external source(s); a number of possible sources, different in their physical nature has been suggested in \cite{P-LH}. The particular driving mechanism assumed here is low-energy, pulsed electron or laser beam(s) incident on a surface. The simplified version of the model is applied to study the relaxation of a periodic surface corrugation. Several extensions of the model are proposed.

cond-mat.mtrl-sci↗