DYNAMICAL SCALING IN CLOSE-TO-EQUILIBRIUM ADSORPTION

Scaling of the hysteresis loop in a close-to-equilibrium adsorption-de sorption (CEAD) process is explored. Wie consider the response of the CEAD process to a chemical potential which varies harmonically with ti me, <(mu)over tilde> = mu(av) + mu(0) sin(2 pi t/tau). mu(av) correspo nds to the coverage v = 1/2 at equilibrium. The cycle time tau is assu med to be sufficiently large so that the system is in thermal equilibr ium at all times. The area A of the adsorption-desorption cycle loop s cales as A proportional to mu(0)(alpha) tau(-beta). We show that for g rowth-controlled hysteresis (GCH), i.e. in the limit of a small nuclea tion time tau(n) much less than tau, alpha = 1/2 and beta = 1/2 for GC H, and confirm this prediction by numerical simulation of a simple mod el. Possible experimental checks of these predictions are discussed.