From X-ray diffraction data you get only structural information. But the structure of material contains the information about toplogical or geometrical frustration. For example if the structure contains traingles, hexagons (honeycomb, Kagome) or tetrahedra (pyrochlore, spinnel etc.) then the antiferromagnetic interactions may be frustrated. Ferromagnetic interaction is not frustrated even on these geometries. But laboratory XRD cannot give you any information about the nature of magnetic interaction directly. For that you must do neutron scattering or other magnetic measurements. Synchrotron X-ray might give you some magnetic information, although such investigations are not at all easy. So in summary XRD can give you the information about the topological or geometrical frustration but that is not enough for the system to be definitely frustrated. You must aso do magnetic measurements.

You must remember that only the perfect triangles and tetrahedra give rise to geometrical or topological frustration but not the distorted ones. If the structure contains such distorted units then it may manage to get rid of magnetic frustration. In some case nearest neighbor interaction can be frustrated by next nearest neighbor interaction can remove the magnetic frustration.

Now Nilesh, do some homework. Go to the library and get the following review articles:

1. Strongly geometrically frustrated magnets, A.P. Ramirez, Annu. Rev. Mater. Sci. 24, 453 (1994).

2. Magnetic pyrochlore oxides, J.S. Gardner, M.J.P. Gingras, J.E. Greedan, Rev. Mod. Phys. 82, 53 (2010).

and read them very carefully. If you do nt understand anything then please come back to me.

Thanks Dr. Chatterji, I have already downloaded your suggested articles and following them now. I will surely get back to you for further discussion.

Now Dr. Chatterji, as I have checked your suggestions and comments, want to ask you about my concerns. You had mentioned earlier that "....So in summary XRD can give you the information about the topological or geometrical frustration but that is not enough for the system to be definitely frustrated...." but in the references I have not found the mode of XRD analysis that may reveal some signatures of frustration at least. Can you suggest some references regarding this particular point? For example, a reference showing some signatures of frustration from XRD? As I do not have access to the neutron scattering....I reallly need some suggestions....Can you Help?

You can determine the crystal structure of your sample from X-ray diffraction data. You then know whether the structure contains magnetic atoms forming triangles or tetrahedra. If it is so then check whether the magnetic atoms are on a triangular, honycomb, Kagome, pyrochlore or spinnel lattice. If it is so and if the triangles are reseanably isosceles then there is good reason to suspect that your system may be frustrated. You should then measure susceptibility of your sample and then determine Curie-Weiss temperature theta. If you know that the system does order with Neel temperature T_N and if you find theta/T_N is much larger than 1 then the system is definitely frustrated. If you do not know the T_N values then you have measure it by specific heat or other laboratory methods (even your susceptibility data can give T_N). Do not tell me that you do not have the possibility of doing neutron diffraction because I know that there is a powder diffractometer at BRAC run by University Consortium. You should write a proposal and ask for neutron beam time there. If accepted then they also provide you with travel money. Also you can apply for neutron beam time at the Institut Laue-Lanevin because India is an ILL member country. But then you have write up a very good quality research proposal.

Thanks again for your valuable suggestions. The material is CuCrO2 and the lattices are triangular. Rietveld is also telling me the similar thing. I can definitely check the Neel temperature and its variation upon doping with PPMS and relate it with the relaxor dispersions I have got.

My present guide also have advised me to prepare a write up for using the BARC powder diffractometer. I am definitely going to try for it. Dr. Chatterji, I sincerely thank you again for giving me relevant and important suggestions.