Oxidation of the Fe(111) surface covered with carbon or nitrogen

The oxidation of an Fe(111) surface covered with carbon or nitrogen was studied using the AES method. The rate of oxidation depends on the form of the carbon or nitrogen. The oxidation rate of an iron surface precovered with an atomic non-metal or implanted with a non-metal is similar at the initial stage (θO<1) to that of a clean iron surface. The oxidation process is inhibited by the adsorbed non-metal atoms at higher oxygen coverage and for implanted samples depends on the amount of non-metal atoms in the subsurface layer. There is an exponential dependence between the oxidation rate and the nitrogen concentration on the surface of the sample implanted with nitrogen. parent rate of oxidation of the iron nitrides is lower than for the clean iron surface at the initial stage of the process. When the oxygen coverage θO ranges from 1 to 2, the oxidation of iron nitrides is similar to that of the clean iron surface. the formation of the iron oxide layer, the nitrogen and carbon atoms remain under this layer.