Dear Zhang, If you are rich, you can use isotopes of Fe/Ni with different coherent scattering lengths in order to improve the contrast. "Contrast variation" is quite common in small angle scattering and diffraction on non-crystalline solids, but also for diffraction studies on crystals with H and B you even mostly use D and 11B in order to reduce incoherent scattering or absorption. Andreas
Ling Fei Zhang wrote: >Dear all, > >Recently, one of my friends ask me, coz he is neutron stranger, and his question is >about one of his project in which they are studying the nanometer-sized domain effect >on Nickel ferrite, NiFe2O4, different from conventional formula and occupancy which >are used to describe the stoichiometry and they found significant anomalous evolution >with the different grain sizes. the exiting techniques, Mosbauer Spectrum and XRD >analysis tell them quantitatively the changes of Fe partial occupancy, however, both >the Mosbauser spectrum and XRD have no capability to study Nickel partial occupancy >situation due to the nature of Mosbauer spectrum and closeness of atomic number. > >Recently they asked me the possibility of neutron diffraction, and since the they use >the natural abundance Nickel and iron as the precursor of sample preparation, so >unfortunately, the similarity of coherent scattering length between the Ni and Fe >makes trouble again, and there is no good perspective for this kind of set-up, though >there seems a isotope substitution solution which presumably makes a good contrast, >however, for the moment, they didn't give priority to this idea. > >What I am looking for is if there is any solution to study the the compound with >close neutron scattering length, I supposed to see, there is some clever method to >solve this issue based on the tips of data analysis from neutron diffraction, or any >others? > >Many thanks! > > >Best Regards, >Lingfei Zhang >********************************** >Neutron Scattering Physics Group >Institute for Materials Research >Maxwell Building 111 >University of Salford >Salford, Greater Manchester >United Kingdom M5 4WT >Tel:0161 295 4633 >Facsimile:0161 295 5147 >Email:[EMAIL PROTECTED] >********************************** > > > > -- Dr. Andreas Leineweber Max-Planck-Institut fuer Metallforschung Heisenbergstrasse 3 70569 Stuttgart Germany Telephone: +49 (0)711 689 3365 Telefax: +49 (0)711 689 3312 [EMAIL PROTECTED] http://www.mf.mpg.de/de/abteilungen/mittemeijer/english/index_english.htm
