[Ifeffit] EXAFS of solid-solution alloy

[Chongchong Mellon]

Hi all,

 I have some problems in analyzing the EXAFS of solid-solution alloy, let
us define as A0.5B0.5. I have searched the mailbox but cannot find similar
discussion yet. So I post the question here and hope to get some suggestion
from you.



   1. A and B are immiscible metals from the phase diagram, which means
   that I couldn’t get the bulk A0.5B0.5 as a standard reference. In this
   case, how can I estimate the amp for the K-edge of A or B?
   2. A and B are very near (atomic number B-A = 2) in the periodic table.
   So their lattice parameters are quite close to each other. In this case,
   when I tried to fit the 1st shell use A-A and A-B paths at the same time,
   the Happiness parameter becomes worse and the coordination number of A-B is
   not realistic (large errors!).  If I fit with only the A-A path or A-B
   path, I get a good fit. However, atomic resolution STEM-EDX maps show the
   homogenous distribution of both A and B atoms. The A-A and A-B bond might
   have an equal ratio. In this case, how can I do the fitting?


Thank you very much in advance!


Sincerely,

Chong
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