High resolution powder diffraction on Sm based pyrochlores

Magnetic frustration is a hot topic in solid state physics, mainly due to the topological new phases of matter that frustration mechanisms can drive (vide Physics Nobel Prize 2016). We focus our research on the cubic Fd-3m, Sm2B2O7 pyrochlore coumpounds (B=Ti, Zr, Sn). Mainly due to the the Samarium high absorption cross section, no studies of Sm compounds using neutrons are reported in literature. We have synthesised 154 Sm isotope enriched samples, what overcome this problem in a great extent. After x-ray diffraction and bulk characterisations of our sample, we believe that structure refinements of high resolution neutron diffraction data is the missing prove of our sample correct stoichiometry, especially on what concerns oxygens vacancies and ion substitutions. Those two factors are known to play a crucial role in the magnetic frustration at low temperatures.