Band Structure and the Titanium LII, III X-Ray Emission and Absorption Spectra from Pure Metal, Oxides, Nitride, Carbide, and Boride

Publisher Website
Google Scholar
Abstract
The titanium LII, III x-ray emission and absorption spectra (λ∼27.5 Å) from pure metal, oxides, nitride, carbide, and boride have been investigated using a plane-crystal vacuum spectrometer with electron-beam excitation and flow-proportional counter detection. Emission spectra were studied over a wide range of accelerating voltages and takeoff angles, showing that satellite emission and self-absorption effects can significantly distort the band shapes and energy positions of intensity maxima. A replica of the LII, III absorption spectrum can be constructed solely from emission spectra affiicted with widely different amounts of self-absorption. The LII, III emission spectra from the oxides, nitride, and carbide exhibit an important crossover transition from the 2p level of the anion to the LII and LIII levels of titanium. Results indicate formation of a 3d band in titanium compounds which is only partially filled, giving rise to metallic conduction. X-ray data is compared to density of states calculations for TiO, TiN, and TiC. The energy shifts of emission bands and absorption edges indicate a transfer of charge from titanium to anion in the oxides, nitride, and boride but that in TiC there is a transfer of charge from carbon to titanium. Energy separations between anion 2p band and titanium 3d band are measured and it is shown that both bands contribute significantly to the TiLII, III spectra from the compounds.