Non-thermal surface roughening in catalytic reactions

Abstract

We identify a new non-thermal, purely dynamic mechanism of surface roughening, possible in exothermic catalytic reactions when the adsorption or reaction energy is transferred to substrate atoms. This “exothermic” mechanism can induce thermodynamically allowed roughening at T> T R ( T R is the roughening temperature), when the latter is kinetically hindered to occur through thermal excitation. Competing with thermal smoothing, it can also induce roughening at T< T R. Using Monte Carlo simulations of the 2A+B 2→2AB reaction on the substrate described in the framework of the restricted-solid-on-solid model, we show that in both cases the mean-square surface-height difference increases with time as w 2∝ ln t .