Abstract:
X-ray absorption Ni K-edge spectra are recorded for the following systems: Ni metal, Ni(NO3)(2).6H(2)O, Ni-3(PO4)(2).6H(2)O, NiSO4.6H(2)O, NiCO3, NiO and La2NiO4 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 Delta E = A(0) + A(1)q + A(2)q(2) + A(3)q(3) + A(4)q(4) between the chemical shift, Delta E, and the partial charge, q, has been suggested. The discrepancy in the shift of NiO and La2NiO4 has also been discussed.