Dear Yuan
Probably not quite answering your question, but it would seem to me that you may have a chance to see XANES changes that could be indicative for the existence
of these ‘blobs’. Unfortunately the paper you attached does not contain any information about the unoccupied DOS, so it is difficult to make a strong statement. Certainly the local coordination geometry around the Al centres seems to vary.
It would seem to me that there is not enough electron density concentrated in the ‘blobs’ to act as additional EXAFS scatterers. Perhaps they influence multiple
scattering … Might be worth running a FEFF analysis of scattering paths and amplitudes (but will FEFF predict those blobs alright?).
Sven
--
Dr Sven L.M. Schroeder (mailto:s.schroeder@manchester.ac.uk)
Reader
School of Chemical Engineering and Analytical Science (CEAS)
The University of Manchester, Manchester M13 9PL, United Kingdom
Also at:
School of Chemistry, The University of Manchester, Manchester M13 9PL, United Kingdom
Tel +44 (161) 306 4502
Fax +44 (161) 306 8867
Office: Room C57 (Jackson's Mill)
DISCLAIMER
The views expressed within this message are those of the sender, not those of The University of Manchester or one of its units. While all emails and attachments are scanned
for viruses before sending, we cannot accept any responsibility for viruses, so please scan all emails and attachments. This email is intended for the addressee only. If you are not the intended recipient, please notify the sender and delete this email immediately.
From: ifeffit-bounces@millenia.cars.aps.anl.gov [mailto:ifeffit-bounces@millenia.cars.aps.anl.gov]
On Behalf Of Ping, Yuan
Sent: 06 February 2012 19:57
To: XAFS Analysis using Ifeffit
Subject: [Ifeffit] XAFS for electride
Dear XAFSers,
Recently there has been a growing interest in the electride phase of sp-bonded materials at extremely high pressures >Mbar (see attached paper for example). This
phase is characterized by a matrix of positive ions and interstitial electron blobs. I am wondering how XAFS signal would change when these electron blobs are present. The x-ray diffraction probably won't detect them directly. But XAFS might be able to show
their existence if they behave like additional scattering centers.
Any thought or information would be appreciated.
Yuan