Magnesium binding energy

Since the K radiation emitted from a magnesium anode consists of the intense Kbinding energies by 8.0 and 10.2 eV [20]. The satellites excited by the Kas and K<,6 lines are usually too weak to be observed. Similar features can be observed in XPS spectra excited using Ko, X-rays from aluminum. 

Ahmad studied specimens of an Al-Li-Cu-Mg-Zr alloy designated 8090 in the form of specimens between 1 mm and 3 mm in thickness cut from an extruded bar of cross-sectional dimensions 51 mm x 25 mm. An XPS spectrum of the surface of a sample oxidized for 5 min at 530°C in air is shown in Figure 2.6. In addition to the peaks of carbon, oxygen and magnesium, there is a lithium (Li Is) peak at 56eV binding energy. 

Table 6.3 Contributions to the binding energy (in Ry per atom) of sodium, magnesium, and aluminium within the second order real-space representation, eqn (6.73), using Ashcroft empty-core pseudopotentials. L/gf is defined by eqn (6.75). The numbers in brackets correspond to the simple expression, eqn (6.77), for = 0) and to the experimental values of the binding energy and negative cohesive energy respectively.

Sodium-24 (23.990 96 u) decays to magnesium-24 (23.985 04 u). Determine (a) the change in the binding energy per nucleon (b) the change in energy that accompanies the decay. 

The XPS data were obtained with an extensively modified AEI ES-100 photoelectron spectrometer. The samples were analyzed at a pressure typically < 10 g Torr. A magnesium anode (1253.6 eV) was used as the excitation source. The analyzed sample area was of the order of 5 mm2. Survey scans from 0 to 1000 eV were first obtained for each sample to confirm that only the expected elements were present on the fiber surfaces. Subsequently, high resolution spectra were obtained by slowly scanning — 20 eV binding energy windows that included the Si 2p, Al 2p, Ca 2p, B Is, O Is, and C Is photoelectrons, respectively. Integrated peak areas of the photoelectron spectra were determined. The sensitivity factors, which were independently obtained on this spectrometer with oxide standards, were then utilized in the determination of the surface atomic percent compositions of the fibers. 

Table 2 Core level binding energies for some magnesium compounds measured by XPS Peak...

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