I am currently analysing data taken on GPPD at IPNS on a sample of SrFe0.8Co0.2O3-delta at 900 Celsius. After performing a Rietveld analysis (GSAS) I can get perfectly acceptable fits while the oxygen content is sensible for any given pO2. The Fe:Co ratio is also as would be expected. The problem, however, is that the Debye-Waller factors for all atoms are rather large and there is some sort of modulation which shows up most clearly when I look at plots which have the background subtracted. I know the effect is not due to some amorphous impurity , nor is it from the ancillary equipment. On a rather simplistic level, I reckon that the modulation arises from some effect on a local scale. I'm wondering if anybody has experience with this sort of thing on perovskite samples, or can give me some tips and hints to tackle this problem, that is assuming that something can actually be done. Thanks in advance. Brian Mitchell Dr. Brian J. Mitchell GRSC IPNS Argonne B360 E205 9700 S. Cass Ave. Argonne 60439-4814 IL Tel- (630)-252-5346 Fax-(630)-252-4163 email- [EMAIL PROTECTED]
