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Abstract: Ba3MgSi2O8, a phosphor host examined for use in white-light devices and plant-growth lamps, was synthesized at 1225°C in air. Its crystal structure has been determined and refined by a combined powder X-ray and neutron Rietveld method (, Z=3, a=9.72411(3)Å, c=7.27647(3)Å, V=595.870(5)Å3; R p/R wp=3.79%/5.03%, χ 2=4.20). Superstructure reflections, observed only in the neutron diffraction data, provided the means to establish the true unit cell and a chemically reasonable structure. The structure contains three crystallographically distinct Ba atoms—Ba1 resides in a distorted octahedral site with S 6 () symmetry, Ba2 in a nine-coordinate site with C 3 (3) symmetry, and Ba3 in a ten-coordinate site with C 1 (1) symmetry. The Mg atoms occupy distorted octahedral sites, and the Si atom occupies a distorted tetrahedral site. [Copyright &y& Elsevier]

Abstract: Sr4AlNbO8 was synthesized at 1500°C in air. The crystal structure was initially determined from powder X-ray diffraction data, and later refined with combined X-ray and neutron diffraction data (P21/c; a=7.17592(2)Å, b=5.80261(2)Å, c=19.7408(1)Å; β=97.5470(1)°, V=814.869(3)Å3, Z=4, R p/R wp=10.04%/13.18% for X-ray data, 4.40%/5.67% for neutron data, and 7.71%/10.74% in total with χ 2 of 3.76, 23°C). The crystal structure is a new structure type and may be described as a three-dimensional polyhedral network resulting from the corner-sharing of NbO6 and Sr1O6 octahedra and AlO4 tetrahedra. Also, the other strontium atoms (Sr2, Sr3, and Sr4) occupy the larger cavities surrounded by oxygen atoms to form nine, eight, and 11 coordination, respectively. Considering that Sr, Al, and Nb atoms are crystallographically distinct in terms of interatomic distances and polyhedral coordination, Sr4AlNbO8 can be regarded as a stoichiometric compound. [Copyright &y& Elsevier]

Abstract: Ba11W4O23 was synthesized at 1300°C, followed by quenching with liquid nitrogen. The crystal structure, which was known to be cryolite-related but has remained unclear, was initially determined by single-crystal X-ray diffraction for the isostructural Ru-substituted compound Ba11(W3.1Ru0.9)O22.5, which was discovered during exploratory synthesis in the Ba–Ru–O system. The structure of Ba11W4O23 was refined by a combined powder X-ray and neutron Rietveld method (Fd-3m, a=17.1823(1)Å, Z=8, R p=3.09%, R wp=4.25%, χ 2=2.8, 23°C). The structure is an example of A-site vacancy-ordered 4×4×4 superstructure of a simple perovskite ABO3, and it may be written as (Ba1.75□0.25)BaWO5.75□0.25, emphasizing vacancies on both metal and anion sites. The local structure of one of two asymmetric tungsten ions is the WO6 octahedron, typical of perovskite. The other tungsten, however, is surrounded by oxygen and anionic vacancies statistically distributed over three divided sites to form 18 partially occupied oxygen atoms (∼30% on average), represented as WO18/3. The A-site cation-vacancies are ordered at the 8a (, , ) site in between adjoining WO18/3 polyhedra which form 1-D arrangements along [110] and equivalent directions. In situ high-temperature XRD data have shown that the quenched Ba11W4O23 at room temperature is isostructural to the high-temperature phase at 1100°C. [Copyright &y& Elsevier]

Abstract: A new lithium cobalt metaphosphate, LiCo(PO3)3, is reported for the first time, which was discovered during the exploratory synthesis in Li–Co–P–O system by solid state reaction. The structure has been refined by powder X-ray Rietveld refinement method (P212121, a =8.5398(2)Å, b =8.6326(2)Å and c =8.3520(2)Å, Z =4, R p =13.6%, R wp =19.4%, R exp =17.7%, S =1.11, χ 2 =1.23). It is isostructural with LiM(PO3)3 (M=Fe, Cu). It contains (PO3)1− chains with the Co atoms localized in the octahedral sites, bridging four neighboring chains. The magnetic susceptibility measurement showed a typical paramagnetic behavior of high spin of Co2+, following the Curie–Weiss law in the temperature range of 5–300K. Unlike the olivine type lithium cobalt phosphate, LiCoPO4, cyclic voltammetry of LiCo(PO3)3 assembled in the coin-type cell showed no electrochemical activity in the voltage region of 1–5V versus Li/Li+. [Copyright &y& Elsevier]

All-Solid-State Batteries: New Cost-Effective Halide Solid Electrolytes for All-Solid-State Batteries: Mechanochemically Prepared Fe3+-Substituted Li2ZrCl6 (Adv. Electrodes, halides, ionic conductivities, solid electrolytes, solid-state batteries Keywords: electrodes; halides; ionic conductivities; solid electrolytes; solid-state batteries EN electrodes halides ionic conductivities solid electrolytes solid-state batteries 1 1 1 03/27/21 20210325 NES 210325 In article number 2003190, Kyung-Wan Nam, Yoon Seok Jung and co-workers develop a new halide solid electrolyte, Fe SP 3+ sp -substituted Li SB 2 sb ZrCl SB 6 sb , that is mechanically sinterable, (electro)chemical-oxidation tolerant, and free of rare-earth metals. [Extracted from the article]