Ag L₃-Edge X-ray Absorption Near-Edge Structure of 4d¹⁰(Ag⁺) Compounds: Origin of the Edge Peak and Its Chemical Relevance

Abstract

A peak appearing at the L(2,3) X-ray absorption edge often provides the number of empty d states of the X-ray absorbing atoms. Ag(+) compounds have a d(10) state (no d empty states) but show a small peak at the edge. In this research, we systematically studied the edge peak of Ag(+) compounds to understand its origin on the basis of the molecular orbital picture and to obtain a relation of the edge peak intensity to chemical and physical quantities. The edge peak can be formally assigned to the transition from 2p to 5s enhanced by the s-d hybridization. The peak intensity has a negative correlation with a coordination charge but has a positive correlation with the strength of the covalent bond, which is in the reverse order to the other d(n) (n < 10) elements.