An Electron and X-Ray Powder Diffraction Study of the Defect Fluorite Structure of Mn0.6Ta0.4O1.65

Hydrothermal synthesis and photoluminescence of Ce3+ and Tb3+ doped La2Sn2O7 nanocrystals

“…It is well known that four main peaks (2 2 2), (4 0 0), (4 4 0) and (6 2 2) are characteristic of pyrochlore structure. Although similar diffractions were also observed in the defect fluorite structure [20], the reflections from the crystallographic planes (3 3 1) and (5 1 1) of the pyrochlore structure are also found in the patterns. We can confirm that the as-prepared samples possess pyrochlore type structure [21].…”

Microdomains and Diffuse Scattering in K2In12Se19

“…Circular features of di!use scattering have been reported frequently in recent years, e.g., for quasicrystals (5) and many compounds related to the #uorite-type structure ( (6) and references quoted therein) including the important oxygen ion conductors CSZ (7) and YSZ (8). In the case of the #uorite phases several experimental methods and simulation procedures were used; however, no unifying model of the real structure could be established despite very similar di!use features for many compounds with di!erent compositions.…”

Single Crystal Refinement of the Incommensurately Modulated Mn0.55Ta0.45O1.7, an Oxygen Deficient Fluorite Type Compound

“…This indicates that some sort of nucleation takes place in the disordered compound and that this nucleus of the incommensurately ordered structure starts at a certain time to grow and eventually crystallize in a modulated long-range ordering. This model could explain the diffuse scattering obtained from the disordered compound as well as the model, suggested in a previous paper, that the structure would be built up by microdomains of a pyrochlore-type structure [1].…”

“…Previous thermogravimetric measurements showed however that the Mn 0.6 Ta 0. 4 [1]. A comparison of EDP's for the disordered and the modulated compound is given in Fig.…”

“…The second phase, Mn 0.6 Ta 0.4 O 1.65 , has a cubic fluorite average structure with the space group Fm3m, a = 4.9826(3) A Ê , and a total vacancy concentration of 17.5% on the oxygen atom sites. It exhibits considerable diffuse scattering, which has been thoroughly investigated and described in a previous paper [1].…”