Artículo
Metallic-thin-film instability with spatially correlated thermal noise
Fecha de publicación:
01/2016
Editorial:
American Physical Society
Revista:
Physical Review E
ISSN:
2470-0053
Idioma:
Inglés
Tipo de recurso:
Artículo publicado
Clasificación temática:
Resumen
We study the effects of stochastic thermal fluctuations on the instability of the free surface of a flat liquid metallic film on a solid substrate. These fluctuations are represented by a stochastic noise term added to the deterministic equation for the film thickness within the long-wave approximation. Unlike the case of polymeric films, we find that this noise, while remaining white in time, must be colored in space, at least in some regimes. The corresponding noise term is characterized by a nonzero correlation length, c, which, combined with the size of the system, leads to a dimensionless parameter β that accounts for the relative importance of the spatial correlation (β∼ c-1). We perform the linear stability analysis (LSA) of the film both with and without the noise term and find that for c larger than some critical value (depending on the system size), the wavelength of the peak of the spectrum is larger than that corresponding to the deterministic case, while for smaller c this peak corresponds to smaller wavelength than the latter. Interestingly, whatever the value of c, the peak always approaches the deterministic one for larger times. We compare LSA results with the numerical simulations of the complete nonlinear problem and find a good agreement in the power spectra for early times at different values of β. For late times, we find that the stochastic LSA predicts well the position of the dominant wavelength, showing that nonlinear interactions do not modify the trends of the early linear stages. Finally, we fit the theoretical spectra to experimental data from a nanometric laser-melted copper film and find that at later times, the adjustment requires smaller values of β (larger space correlations).
Palabras clave:
Metallic Thin Films
,
Surface Instability
,
Thermal Noise
,
Stochasticity
Archivos asociados
Licencia
Identificadores
Colecciones
Articulos(CIFICEN)
Articulos de CENTRO DE INV. EN FISICA E INGENIERIA DEL CENTRO DE LA PCIA. DE BS. AS.
Articulos de CENTRO DE INV. EN FISICA E INGENIERIA DEL CENTRO DE LA PCIA. DE BS. AS.
Citación
Diez, Javier Alberto; Gonzalez, Alejandro Guillermo; Fernández, Roberto; Metallic-thin-film instability with spatially correlated thermal noise; American Physical Society; Physical Review E; 93; 1; 1-2016; 1-12; 013120
Compartir
Altmétricas