Further evidence in support of new empirical relation for chemical shift and effective charge in the X-ray absorption edge shifts

Abstract

When a compound is formed, re-arrangement of electrons takes place. Consequently, the energies of core levels as well as outer states are altered. As a result, the position of the absorption edge undergoes shift in its energy. This shift in energy, when measured with respect to the pure metal, is called chemical shift, represented by ΔE. The concept of effective charge is found to be useful to understand chemical shift in X-ray absorption spectra. Validity of new empirical relation ΔE=aebq, between the chemical shift ΔE and effective charge ‘q’, has been demonstrated successfully using its linearized form ln|ΔE|=ln|a|+bq for a variety of binary and ternary cobalt compounds. As the proposed equation is empirical in nature, it is always desirable to examine its validity to as many systems as possible. The results obtained validate the correctness of exponential relation for chemical shift ΔE and effective charge ‘q’ proposed earlier.