[Ifeffit] XAFS for electride

[Sven Schroeder]

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


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Dr Sven L.M. Schroeder (mailto:s.schroeder at manchester.ac.uk)

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From: ifeffit-bounces at millenia.cars.aps.anl.gov [mailto:ifeffit-bounces at 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


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