Theory of Auger relaxation energies in metals

Abstract

A theory of the Auger parameter $\xi$ is introduced and used to interpret measurements on the $3d$ transition metals. This parameter is the combination of an Auger energy and related core-level binding energies which formally eliminates the contributions of chemical shifts and reference levels, permitting the unambiguous extraction of a relaxation energy from measured quantities. The value of $\xi$ is the result of two competing effects which cancel approximately in some cases, but not in others. This leads to an interesting variation of $\xi$ with atomic number. Our parameter-free calculations describe both the magnitude of this quantity and its strong increase at the end of the transition series, where the character of the screening charge changes from $d$-like to $s$-like.