Fractions of a diamond surface covered by radical and diradical sites were calculated with use of a Monte Carlo kinetic method. The formation of surface radicals was assumed to be governed by two gas-surface reactions: abstraction of a surface hydrogen atom by a gaseous hydrogen atom and the addition of a gaseous hydrogen atom to the surface radical formed. The underlying principle of the employed Monte Carlo method is that the probability of a given gas-surface reaction event is assumed equal to the product of the conditional probability of reaction to occur upon the corresponding collision between a given gaseous species with a given surface site and the probability of such collision. This method provides a formalism for description of gas-surface reaction kinetics capable of accounting rigorously for steric factors.

• Received 22 July 1991

DOI:https://doi.org/10.1103/PhysRevB.45.9455