[Ifeffit] Bond length determination EXAFS vs XRD

Frenkel, Anatoly frenkel at bnl.gov
Fri Nov 27 13:12:15 CST 2009

XRD measures interplanar spacing, and XAFS - interatomic distances, and they are not the same if disorder is present. Look for articles by Boyce and Mikkelsen, Jr., in Phys Rev B in 1980's who were the first discussing these concepts in GaAs-InAs semiconductors and also KBr-RbBr ionic salts. 
They showed that the average structure ascertained by diffraction differs from the local structure measured by EXAFS.
Modern day high energy XRD/PDF measures interatomic distances more accurately than Bragg peak analysis can do but how accurately it agrees with EXAFS is still subject of debates.


From: ifeffit-bounces at millenia.cars.aps.anl.gov on behalf of Joseph Washington
Sent: Fri 11/27/2009 2:08 PM
To: XAFS Analysis using Ifeffit
Subject: [Ifeffit] Bond length determination EXAFS vs XRD

Happy Thanksgiving All!

Can someone, send me some references which explains some of the reasons
why the bond lengths fitted in EXAFS would be different from that fitted
in XRD (assuming that we implemented the crystal model predicted by XRD
correctly in Artemis)?

I would really appreciate this!

Joseph Washington
Research Assistant
Department of Physics
North Carolina State University
431 Riddick Hall
Raleigh, NC 27695-8202
email: jswashin at ncsu.edu
Ifeffit mailing list
Ifeffit at millenia.cars.aps.anl.gov

-------------- next part --------------
A non-text attachment was scrubbed...
Name: winmail.dat
Type: application/ms-tnef
Size: 4529 bytes
Desc: not available
URL: <http://millenia.cars.aps.anl.gov/pipermail/ifeffit/attachments/20091127/dfddaad4/attachment.bin>

More information about the Ifeffit mailing list