An unusual orbital state was recently proposed to explain the magnetic and transport properties of Ba3CoRu2O9. This state contradicts to the first Hund's rule and does not realize in the system under consideration because of a too small crystal-field splitting in the t2g shell. A strong suppression of the local magnetic moment in Ba3CoRu2O9 is attributed to a strong hybridization between the Ru 4d and O 2p states.

See Also: The crystal and magnetic structures of Ba3NiRu2O9, Ba3CoRu2O9, and Ba3ZnRu2O9

By:  P. Lightfoot 1, P.D. Battle

The two theta range 10-90 deg is not sufficient for a Rietveld Refinement. It is better to run from 5-140 deg. The peak at  ~70 deg cannot be fitted according your current model. It is possible the symmetry of your model is not suitable or prefer orientation presents. Try to check it. This should help you improve your refinement. 

The two theta range that i have used shouldn't be a major concern. If u look at examples given in the full prof manual, few of the examples have a similar theta range. Also i have already fit XRD data for the same sample in the same theta range.I have already refined preferred orientation parameter. And also symmetry of these systems are very well reported. So no problem with that.Its the intensities at high theta which are not matching.

It's not the intensity is the problem but the peak shape itself. At lower angle it gave the same problem, but more pronounced as the peak getting wide and tall.

The best possible Chi^2 for u diffractogram is about 3 if use split width-shape asymmetric type in voigtian profile function.

Try software that implementing FPA such as Topas or BGMN.

Are you talking about the split pseudo voigt function in full prof?? Its because i tried that shape and the fit going worse.