http://nova.newcastle.edu.au/vital/access/services/Feed ${session.getAttribute("locale")} 5 http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:12185 Professional Doctorate - Doctor of Business Administration (DBA) 2012-12-07T04:57:22.932Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:1235 We have measured the ratio of the population of Ni neutral atoms sputtered into the a³D₃ metastable state to that into the a³F₄ ground state using two-color ionization schemes. The ratio is 2.27±0.31 for Ni, 2.34±0.17 for Ni₃Al, and 2.61±0.27 for NiAl. Within experimental error, we observed no effect of the valence band electron structure on the population ratio. We suggest that sputtered atoms should experience resonant neutralization and nonradiative relaxation. Before neutralization, departing Ni ions from the surface have an electron configuration of 3d⁹ or 3d⁸4s¹. The 4s electron orbital of the departing ions captures a valence electron and formed nascent Ni atoms in the D (3d⁹4s¹) and F (3d⁸4s¹) states, respectively. The population inversion can be attributed to the character of ions and atoms of Ni. Because of the character of Ni ions, most of the ejected nascent Ni atoms are in the D state. The character of Ni atoms leads to a low relaxation rate of the D to F state. Many of the nascent Ni atoms in the D state can survive and so the population inversion was observed. 2010-04-27T06:39:01.379Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:5509 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(100) and NiAl(110). 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. 2010-04-27T04:43:14.983Z ]]>