Persistence in reactive-wetting interfaces.

In this paper, we report on persistence results of reactive-wetting advancing interfaces performed with mercury on silver at room temperature. Earlier kinetic roughening studies of reactive-wetting systems at room temperature as well as at high temperatures revealed some limited information on the spatiotemporal behavior of these systems. However, by calculating the persistence exponent, we were able to identify two distinct kinetic time regimes in this process. In the first one, while the interface is moving but its width is not yet growing, the persistence exponent is θ=0.55±0.05, which is typical for a random, noisy behavior. In the second regime, there is an effective growth of the interface width with a growth exponent β=0.67±0.06 followed by saturation, according to the Family-Vicsek description of interface growth. The persistence exponent in this regime is θ=0.37±0.05, which indicates that the relation θ=1-β seems to hold even for this nonlinear experimental system.