The result of this is that the final peak possesses an asymmetric character, due to a multitude of final states each having lost a different amount of kinetic energy (and hence increasing effective binding energy of the photoemission). Figure 3: Shake-up processes in conducting material When our LUMO is a conduction band, however we have a continuum of possible shake-up structures which may leave the ion in a variety of states (figure 3). All XPS spectra were calibrated using the universal hydrocarbon contamination C 1s peak at 284.8 eV. We have discussed shake-up peaks in another section, wherein a photoemission can excite the resulting ion to an energy state slightly above the ground state, typically a few eV. XPS measurements were performed on an ULTRA (Kratos Analytical) spectrometer under ultrahigh vacuum (10 7 Pa) using monochro-mated Al Ka radiation (hm 1486.6 eV) operated at 210 W. Figure 2: Nickel valence energy levels and conduction band The LUMO is the conduction band, a continuum of unfilled molecular energy levels (figure 2). The 1000 PEAK Battery Amp Jump Starter has enough power to jump start most 12 volt. The valence band (equivalent to the HOMO) in nickel consists of the 4s and 3d electrons. 2015 CAT 289D Skid Steer Loader - Crawler bucket, high flow XPS. When we think about metals/conductive materials we think of the energy levels as bands. This is the result of final state effects within the metal, caused by the conduction band. Metals and other conductive materials such as graphene, however, may in fact produce asymmetric peaks (such as the nickel peak in figure 1).
Figure 1: (Left) Symmetric O 1s XPS peak and (Right) Asymmetric Ni 2p XPS peak. For example, the oxygen peak in figure 1. Typically, spectral peaks from photelectron emission exhibit a symmetrical lineshape, representing a range of energies characterised by the full-width at half maximum.