Adsorption mechanisms and electronic and magnetic properties of oxygen on iron tetranitride

Abstract

The oxide layer on iron nitrides restricts the conductivity of electrode materials. The adsorption and dissociation processes of O2 on the Fe4N have been analyzed by using first-principles. Comparing all the O2Fe4N isomers, we find that O atom prefers to locate at the center site of Fe–Fe–Fe plane which stays away from N atom. It means that O2 molecule is dissociated on the surface of Fe4N molecule. Endothermic and exothermic processes occur with the adsorption and decomposition of O2 on the surface of Fe4N. All the O2Fe4N clusters still present higher kinetic activity. For the O2Fe4N clusters, the internal electrons transfer from 4[Formula: see text] to 3[Formula: see text] and 4[Formula: see text] orbitals which are obviously more than those transfer to the other atoms. O atoms acquire less electron from nearby Fe atoms which confirms that the adsorption of O2 on Fe4N is a physical adsorption process. The average spin of the ground-state O2Fe4N clusters is 1.805 [Formula: see text]/atom.