Vacancy Induced Electronic States in Some Tantalum Carbide, Boride, Nitride, Silicide and Borocarbide Powders: An X-ray Emission Study

Abstract

The L and M X-ray emission spectra of tantalum carbide, boride. nitride, silicide, aluminide and tantalum-hafnium carbide were found to be complex in nature. These spectra were analysed by a curvefit programme and were found to have three peak structure. The intensity of Lα₂ emission was found to deviate very much from the theoretically predicted intensity. Beside, the main Lα₁ emission around 8115 eV, emission peak around 8145 eV was also observed due to Lα₁ emission. The chemical shift of Lα₂ emission and the variation in its intensities for different compounds as well as the intensities of satellite emission line have been explained on the basis of Coster-Kronig processes leading to vacancy creation, shake off probabilities and molecular orbital formation taking place in these compounds.

Keywords:

• X-ray emission spectra
• Coster-Kronig process
• Satellite emission