Physics – Condensed Matter – Statistical Mechanics
Scientific paper
2011-03-16
Phys. Rev. E 83, 041608 (2011)
Physics
Condensed Matter
Statistical Mechanics
7 pages, 6 figures and 2 tables
Scientific paper
10.1103/PhysRevE.83.041608
In surfaces with grainy features, the local roughness $w$ shows a crossover at a characteristic length $r_c$, with roughness exponent changing from $\alpha_1\approx 1$ to a smaller $\alpha_2$. The grain shape, the choice of $w$ or height-height correlation function (HHCF) $C$, and the procedure to calculate root mean-square averages are shown to have remarkable effects on $\alpha_1$. With grains of pyramidal shape, $\alpha_1$ can be as low as 0.71, which is much lower than the previous prediction 0.85 for rounded grains. The same crossover is observed in the HHCF, but with initial exponent $\chi_1\approx 0.5$ for flat grains, while for some conical grains it may increase to $\chi_1\approx 0.7$. The universality class of the growth process determines the exponents $\alpha_2=\chi_2$ after the crossover, but has no effect on the initial exponents $\alpha_1$ and $\chi_1$, supporting the geometric interpretation of their values. For all grain shapes and different definitions of surface roughness or HHCF, we still observe that the crossover length $r_c$ is an accurate estimate of the grain size. The exponents obtained in several recent experimental works on different materials are explained by those models, with some surface images qualitatively similar to our model films.
Aarao Reis Fabio D. A.
Oliveira T. J.
No associations
LandOfFree
Roughness exponents and grain shapes does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Roughness exponents and grain shapes, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Roughness exponents and grain shapes will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-263623