Optical emission generated by collisions of 5 eV O(3P) atoms with surface-adsorbed hydrazine

Optical emission has been observed corresponding to vibrational bands in the NH (A 3Π→X 3Σ−) electronic transition during collisions of 5 eV, ground-state oxygen O(3P) atoms with MgF2 and Ni surfaces continuously exposed to a beam of hydrazine (N2H4). The NH emission intensity is observed to be about five times greater for MgF2 than for Ni. No dependence on temperature was observed for either surface in the range 240–340 K, implying that the NH-producing intermediate species is tightly bound. The half-lifetime for desorption of hydrazine from each surface was measured. This was found to be 120 min for the MgF2 surface at 240 K, and ≤20 min for Ni. After exposure the surface composition was measured using x-ray photoelectron spectroscopy (XPS) on the exposed and unexposed areas of both targets.