Single-phase Ln4Ni3O8 (Ln = La, Nd) nickelates were synthesized and their crystal structures were determined by Rietveld refinement of powder neutron diffraction data. The crystal structures of these mixed-valent Ni1+/Ni2+ phases belong to the T'-type and are built by intergrowth of LnO2 fluorite layers with triple NiO2 infinite-layer structural blocks. The major driving force of transformation...

Fluorite-structured oxides find widespread use for applications spanning nuclear energy and waste containment, energy conversion, and sensing. In such applications the host tetravalent cation is often partially substituted by trivalent cations, with an associated formation of charge-compensating oxygen vacancies. The stability and properties of such materials are known to be influenced strongly...

Among the superionic conductors that show a Faraday transition - the continuous increase in the ionic conductivity over a range of temperatures - the fluorite structures have enjoyed incisive examinations over the past four decades; yet the fundamental nature of superionicity has remained largely inconclusive. Departing from the traditional quasi-static defect framework, we provide weighty evid...

We performed batch dissolution experiments on different sized granite and biotite in pure water, in order to better understand the source and geochemical behavior of fluoride in groundwater. Very high concentrations of fluoride (up to 6–10 mg/l) were observed from granite leaching. Correlations between leached ions suggest that fluoride possibly originates from dissolution of biotite. After ~50...

Fluorite, barite and calcite are important industry minerals. However, they often co-exist, presenting difficulty in selectively separating them due to their similar surface properties. In this study, valonea extract and sodium fluosilicate were used as depressants to selectively separate them by flotation, with sodium oleate as the collector. The single mineral flotation results showed that va...

The Burpala massif located in the Northern Baikal region contains ore-bearing pegmatites, carbonatites and apatite-fluorite rocks with Zr-Nb-REE-rare-metal mineralization. Considering their petrological, geochemical, geological thermobarochemical features, it was established that were formed from a residual fluid melt containing minor CO 2 , increased P O 5 F. Apatite-fluorite of are similar to...

A new hierarchical approach is presented for elucidating the structural disorder in Ce1-x Gd x O2-x/2 solid solutions on different scale lengths. The primary goal of this investigation is to shed light on the relations between the short-range and the average structure of these materials via an analysis of disorder on the mesocopic scale. Real-space (pair distribution function) and reciprocal-sp...

the data obtained from field and geothermometric studies and also the ree composition of fluorites associated with lead mineralization at the kamar-mehdi mine are compatible with a structurally controlled, fissure filling, epigenetic, hydrothermal origin. homogenization and last ice melting temperatures for primary fluid inclusions trapped in fluorite crystals indicate that the mineralization o...

Use of the tetrahedral ligand tetrakis(4-tetrazolylphenyl)methane enabled isolation of two three-dimensional metal-organic frameworks featuring 4,6- and 4,8-connected nets related to the structures of garnet and fluorite with the formulae Mn(6)(ttpm)(3)5 DMF3 H(2)O (1) and Cu[(Cu(4)Cl)(ttpm)(2)](2)CuCl(2)5 DMF11 H(2)O (2) (H(4)ttpm=tetrakis(4-tetrazolylphenyl)methane). The fluorite-type solid 2...