This work presents a structural investigation of La2-xNdxCe2O7 (x = 0.0, 0.5, 1.0, 1.5, 2.0) using X-ray powder diffraction and total scattering neutron powder diffraction, analysed using Rietveld and the reverse Monte Carlo method (RMC). Ab initio molecular dynamics (MD) modelling is also performed for further investigations of the local order. The main intensities in the neutron diffraction d...

The rare earth elements (REE) are composed of the Lanthanide Series of 15 elements with atomic numbers (57) through (71) and yttrium (39). Because of their geochemical behavior, REE rarely form their own minerals and more commonly are found incorporated within the structure of other minerals. There is growing concern over the economical availability of REE because of their diverse and expanding...

The replacement of tantalum by the couple Zr/W within the RTa-O-N systems (R = Y, Nd, Sm, Gd, Yb), enables the preparation of novel oxide and oxynitride phases in the R-Zr-W-O-N system. R2Zr2-xWxO7+x oxides exhibit the fluorite-type (x<0.9) and scheelite (x  1) structures. Corresponding oxynitride compositions are of the fluorite type and show different colors, for example in the case of ytter...

A combination of (89)Y and (119)Sn NMR spectroscopy and DFT calculations are used to investigate phase evolution, local structure and disorder in Y2Zr2-xSnxO7 ceramics, where a phase change is predicted, from pyrochlore to defect fluorite, with increasing Zr content. The ability of NMR to effectively probe materials that exhibit positional and compositional disorder provides insight into the at...

we report the fabrication of pure CeO2, ZnO and SiO2 deposited CeO2 hybrid core-shell nanoparticles by simple and cost effective co precipitation method. The as synthesized samples were characterized by various experimental techniques such as XRD (X-ray diffraction), FTIR (Fourier Transform Infrared Spectroscopy) and HRTEM (High Field Transmission Tunneling Microscopy) measurements. XRD results...

A new high-pressure phase of U3O8, which has a fluorite-type structure, forms at pressures greater than 8.1 GPa that was confirmed by in situ x-ray diffraction (XRD) measurements. The fluorite-type U3O8 is stable at pressures at least up to 40 GPa and temperatures to 1700 K, and quenchable to ambient conditions. Based on the XRD analysis, there is a huge volume collapse (420%) for U3O8 during t...

The weberite structure (A2B2X7) is an anion-deficient fluorite-related superstructure. Compared with fluorites, the reduction in the number of anions leads to a decrease in the coordination number of the B cations (VI coordination) with respect to the A cations (VIII coordination), thus allowing the accommodation of diverse cations. As a result, weberite compounds have a broad range of chemical...

The defect structure of cubic fluorite structured yttria-stabilized zirconia (ZrO2)12x(Y2O3)x has been investigated over the composition range 0.100(4)<x<0.241(10) and temperatures T(K) up to 2780~10! K, using single-crystal specimens. Analysis of neutron and x-ray diffraction data, including both Bragg and coherent diffuse scattering components, has identified three principal types of defects ...