Date: Thu, 26 May 1994 21:09:20 -0500 (CDT)
Subject: Microprobe: Chemical Shifts
From: "Nestor J. Zaluzec-ANL EMCenter"


Re: Chemical Shifts in X-ray Spectra

I haven't kept up with this aspect of the field for
the last few years, however, many moons ago when I was
a younger lad, John Colby (of Magic IV fame) did some work
on the shifts in light element K lines. Duncumb et al did
work in the mid 60's, Holliday did work on carbide phases
around the same time. These shifts are best measured by
WDS (but as a uprobist you know this already). The chemical
shifts are due to the fact that the emission lines are due
to transitions of valence electrons to Kshell vacancies rather
than deeper core levels (ie. L's or M's) to the K shell which
we see in higher atomic number elements.

My suggestion is to look into some of the more recent books
on Bulk X-ray analysis. Love and Scott, or the rewritten
book by Reed (which should be on the market soon). You
should also probably check out the last few years conference
proceedings of the Microbeam Analysis Society.

Nestor Zaluzec
ANL EMCenter