The influence of pd mixing and magnetic interactions on the pre-edge peak intensity at the Co (Ni) K absorption edge in solid solutions

Abstract

In this work, the variation of the pre-edge peak at the Co (Ni) K absorption edge in solid solutions is studied upon dilution. Its intensity is attributed to the number of ground-state configurations with oxygen 2p hole(s) denoted by . Upon dilution, the pre-edge peak intensity grows by about a factor of 1.2 in and about a factor of 2.8 in . This fact is explained by an increase of the mixing. The results obtained are in agreement with the modifications of the local atomic structure around and ions, probed by extended x-ray absorption fine structure (EXAFS), and optical spectroscopies. The correlation between the concentration dependences of the pre-edge peak intensity and the Néel temperature for solid solutions is also discussed.