Radiative lifetimes of the FeO orange system

The ground-state FeO molecules are generated from photolysis of Fe(CO) 5 in a Fe(CO) 5 /M(O 2 or N 2 O)/Rg(He or Ar) mixture using an unfocused weak UV laser beam. The formation of ground-state FeO molecules is identified by a laser-induced fluorescence (LIF) method. The LIF signal from FeO molecules is stronger in O 2 than in N 2 O at the same partial pressures. The radiative lifetimes for seven bands in the FeO orange system are measured. They are substantially different depending on the excited band ranging from 260±30 ns to 590±50 ns.