Additionally, you can use anomalous scattering to increase the contrast between neighbors in the periodic table. This can be done at a synchrotron (some times more accessible than neutron sources).
However if you have a very low dopant concentration (<5%) even neutrons can be of no use if the difference in scattering power is not large enough. For perovskite ABO3 (which I assume is your case, I apologize if not) in general there are very good chemical reasons for a dopant C to go into either A or B site. It's very unfrequent to have doping in both sites at the same time with small amounts of dopant. Frequently small amounts of secondary phases or reduced crystallinity are indications of the dopant not going where expected... Hope this helps Leo Dr. Leopoldo Suescun Prof. Agr (Assoc. Prof.) de Física Tel: (+598 2) 9290648/9249859 Cryssmat-Lab./DETEMA Fax: (+598 2) 9241906 Facultad de Quimica, Universidad de la Republica ,_. | \ | v- ,' \ | ( \__Montevideo, Uruguay -----Original Message----- From: Joerg Bergmann [mailto:em...@jbergmann.de] Sent: Wednesday, December 02, 2009 5:41 AM To: rietveld_l@ill.fr Subject: Re: site occupancy For X-ray/Synchrotron: That depends from the difference of the atomic numbers Z between A and B. If A and B are neighbors in the periodic table, nearly impossible. If the difference is large, you may go down to percents. In the case of neighbors in the periodic table, there is the option of using neutron diffraction. Joerg Am Mittwoch, den 02.12.2009, 12:53 +0530 schrieb deepti kothari: > Hi All, > > Can anyone suggest me --Up to what dopant level (in any system like > ABO3) one can conclusively determine from Rietveld refinement location > of dopant as A or B site based on site occupancy. > > Thanks in advance > > Deepti Kothari > UGC-DAE,CSR, > INDORE > > > > ______________________________________________________________________ > The INTERNET now has a personality. YOURS! See your Yahoo! Homepage. No virus found in this incoming message. Checked by AVG - www.avg.com Version: 8.5.426 / Virus Database: 270.14.88/2538 - Release Date: 12/01/09 07:59:00 No virus found in this outgoing message. Checked by AVG - www.avg.com Version: 8.5.426 / Virus Database: 270.14.88/2538 - Release Date: 12/01/09 07:59:00
