Time-of-flight mass spectra of Ni metastable excited atoms sputtered from Ni(1Â 0Â 0), Ni3Al(1Â 0Â 0) and NiAl(1Â 1Â 0)

Using the resonance multi-photon ionisation (RMPI) technique, we have for the first time studied time-of-flight (TOF) mass spectra of Ni neutral atoms sputtered into the a3F4,3,2 atomic states (F states) and the a3D3,2,1 and a1D2 atomic states (D states) from Ni3Al(1 0 0) and NiAl(1 1 0). TOF mass spectra from Ni(1 0 0) have also been measured. For these three surfaces, the TOF spectra of Ni atoms emitted in D states shifted toward a shorter TOF compared to those in F states. The TOF spectra of Ni atoms emitted in different F states are almost the same but the TOF spectra of Ni atoms emitted in metastable D states depend very slightly on the excitation energy of Ni metastable atoms so that the TOF spectra of Ni atoms in the higher energy states include more high energy particles. Finally, the d band structure is shown to have no effect, to within experimental error, on the features of TOF spectra.