I have tried the position of C atom, and i have supposed that could be in
8a,whic is an intersticial position, as Frank says, but you have to
specify the site occupation, which is related to carbon content.
On Fri, October 31, 2008 8:05 am, Frank Girgsdies wrote:
as far as I know, austenite is just a solid solution of a few mole-% of
carbon in gamma-iron. Thus, you essentially need the structure of
gamma-Fe, which is very simple, as it is an fcc metal (space group Fm-3m, a
= 3.6468 A, just one
Fe atom located on 0,0,0).
I found one ICSD entry for austenite.
However, the dissolved carbon is placed sharing
the Fe site in this structure, which I doubt makes sense from the chemical
point of view. I would bet the carbon atoms are actually located
on interstitial sites instead. Anyway, as we are talking about a few MOLE-%
of carbon here, and carbon is much lighter than iron, I think neglecting
the carbon will not make much of a difference (both for the accuracy of the
calculated relative intensities and the quantification in wt-%. Thus, I
would just use gamma-Fe as a replacement for austenite here.
Department of Inorganic Chemistry
Fritz Haber Institute (Max Planck Society)
antonio josé wrote:
I trying analyze phases in a steel sample using X-Ray technique. The
analysis of X-Ray pattern shows that the main phases are ferrite and
austenite. The next step would be quantify these phases by Rietveld
method using TOPAS 3.0. I am looking for cif files for austenite and I
didnt find it in WEB free database or in ICSD database.
Do anyone has this cif file or could tell me where I can find?
Thanks a lot,