Hi JA, I agree with Anatoly that remeasuring in transmission is a good idea, if you have the beam time. But I would also note that the value you have for S02 with the correction is within the realm of possibility, considering the uncertainty: 1.20 - 0.30 = 0.90. And part of the reason for starting with a standard in the first place is to work out some of the other difficulties that may arise; e.g. questions of normalization. If it is not practical for you to remeasure right now, you can try some of the things that can reduce the uncertainty in S02: fitting with multiple k-weights, changing the k-range being fit, fitting multiple coordination shells, etc.. I also just checked a past paper of mine, and see I ended up with an S02 for a set of platinum samples (transmission) of 1.16 +/- 0.05, suggesting that I wasn't doing something quite right (probably not sample preparation or measurement issues, since most of those tend to lower S02). But since that set of samples included a standard, and I was really interested in the differences between samples (including the standard), the fact that I have some systematic error that's causing the S02 to come out a tad large was acceptable, if a bit troubling. The paper is S. Calvin et al., Appl. Phys. Lett. 87, 233102 (2005). --Scott Calvin Sarah Lawrence College P.S. Just as I finished writing this, Matthew Marcus' post came through. I do have Pt foil data in transmission that I can dig up for you, if you'd like. Maybe I'll send it to Matt to put in the database; it's pretty good quality, as I recall (good data out to 20 inverse angstroms or so). At 01:31 PM 12/5/2006, Juan Antonio Maciá Agulló wrote:
Hi all,
I did fits with self absorption corrected data (Fluo and Booth algorithms) and the value for S02 is 1.20 (0.30). It seems that I am not very lucky, if I take an average value (1.20 and 0.50), it should be ok (0.85) jeje, I am joking.
Then...what can I do now?