title: Molten salt synthesis of a mixed-valent lanthanide(III/IV) oxychloride with an unprecedented Sillen X(2)(4) structure: Ce1.3Nd0.7O3Cl.
abstract: A new cerium neodymium oxychloride, Ce1.3Nd0.7O3Cl, has been synthesized by precipitation in a LiCl–CaCl2 molten salt by humid argon sparging. Chemical and structure characterization have been undertaken by powder X-ray diffraction, scanning electron microscopy, high-temperature X-ray diffraction, thermogravimetric analysis, and X-ray photoelectron scattering. This oxychloride crystallizes in space group P4/nmm, a = 3.9848(3) Å and c = 12.467(2) Å, in a new Sillen-type phase represented by the symbol X(2)(4) where “quadruple” fluorite-type layers [M4O6], containing Ce(IV) in “inner” sublayers and both CeIII and NdIII in “outer” sublayers, alternate with double-halide ion sheets. The structure is also described as a stacking of LnOCl and fluorite-type blocks and constitutes the term n = 2 of a possible series (MO2)n(NdOCl)2.
authors.affiliation: Unité de Catalyse et de Chimie du Solide, UCCS UMR CNRS 8181, ENSCL-USTL, Université Lille Nord de France, B.P. 90108, 59652 Villeneuve d'Ascq Cedex, France.
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Vigier
authors.forename: Catherine
authors.initials: C
authors.lastname: Renard
authors.forename: Natacha
authors.initials: N
authors.lastname: Henry
authors.forename: Annabelle
authors.initials: A
authors.lastname: Laplace
authors.forename: Francis
authors.initials: F
authors.lastname: Abraham
mesh_terms: D001128:Argon; D002122:Calcium Chloride / Q000737:chemistry; D002563:Cerium / Q000737:chemistry*; D018021:Lithium Chloride / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D015394:Molecular Structure; D009354:Neodymium / Q000737:chemistry*; D056951:Photoelectron Spectroscopy; D012492:Salts / Q000138:chemical synthesis; D013818:Thermogravimetry; D014867:Water / Q000737:chemistry; D014961:X-Ray Diffraction
chemical_list: D012492:Salts; D014867:Water; D009354:Neodymium; D002563:Cerium; D001128:Argon; D018021:Lithium Chloride; D002122:Calcium Chloride