Local structure of the vacancy disordered fluorite Yb 3 TaO 7 from neutron total scattering

The local structure of the defect, vacancy disordered fluorite Yb3TaO7 has been investigated using neutron total scattering methods. The average structure of Yb3TaO7 is well described in space group Fmm, with unit cell constant a = 5.1872(1) Å, in which Yb and Ta occupy, randomly, the single cation site in a fluorite structure and there is a vacancy concentration of approximately ⅛ on the anion site. Examination of the neutron diffraction data …