Chemical Shift of X-Ray K-Absorption Edge of Ni in Some of its Compounds and its Correlation with Partial Charge

Abstract

X-ray absorption Ni K-edge spectra are recorded for the following systems: Ni metal, Ni(NO$\text{}_{3}$)$\text{}_{2}$ • 6H$\text{}_{2}$0, Ni$\text{}_{3}$(PO$\text{}_{4}$)$\text{}_{2}$ • 6H$\text{}_{2}$0, NiSO$\text{}_{4}$ • 6H$\text{}_{2}$0, NiCO$\text{}_{3}$, NiO and La$\text{}_{2}$NiO$\text{}_{4}$ using a Cauchois-type bent crystal spectrograph. The chemical shift of these systems is correlated with the partial charge determined using Sanderson's method. On the basis of regression analysis a relation ΔE = A$\text{}_{0}$ + A$\text{}_{1}$q + A$\text{}_{2}$q$\text{}^{2}$ -A$\text{}_{3}$q$\text{}^{3}$ + A$\text{}_{4}$q$\text{}^{4}$ between the chemical shift, ΔE, and the partial charge, q, has been suggested. The discrepancy in the shift of NiO and La$\text{}_{2}$NiO$\text{}_{4}$ has also been discussed